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                                                                    Exhibit 10.2

                          REGISTRATION RIGHTS AGREEMENT

         This REGISTRATION RIGHTS AGREEMENT, dated as of July 25, 2003 (this
"Agreement"), is made by and among Sonus Pharmaceuticals, Inc., a Delaware
corporation, with headquarters located at 22026 20th Avenue S.E., Bothell,
Washington 98021 (the "Company"), and the investors named on the signature pages
hereto (the "Initial Investors").

                                    RECITALS:

         A. In connection with the Securities Purchase Agreement dated July 25,
2003 between the Initial Investors and the Company (the "Purchase Agreement"),
the Company has agreed, upon the terms and subject to the conditions of the
Purchase Agreement, to issue and sell to the Initial Investors 3,930,071 shares
of the Company's Common Stock (the "Common Shares") and warrants to purchase up
to 1,965,031 shares of the Company's Common Stock, subject to adjustment (the
"Warrants" and, collectively with the Common Shares, the "Securities").

         B. In order to induce the Initial Investors to execute and deliver the
Purchase Agreement, the Company has agreed to provide certain registration
rights under the Securities Act and applicable state securities laws with
respect to the Securities.

         In consideration of the premises and the mutual covenants contained
herein and other good and valuable consideration, the receipt and sufficiency of
which are hereby acknowledged, the Company and the Initial Investors hereby
agree as follows:

                                   ARTICLE I
                                   DEFINITIONS

         Capitalized terms used and not otherwise defined herein have the
respective meanings given them set forth in the Purchase Agreement. In addition,
as used in this Agreement, the following terms have the following meanings:

         1.1      "Closing Date" means the date on which the purchase of the
Securities is consummated pursuant to the Purchase Agreement.

         1.2      "Common Shares" means the shares of Common Stock sold pursuant
to the Purchase Agreement.

         1.3      "Investors" means the Initial Investors and any of their
transferees or assignees who agree to become bound by the provisions of this
Agreement in accordance with Article IX hereof.

         1.4      "Registrable Securities" means the Common Shares and the
Warrant Shares, and any shares of capital stock issued or issuable from time to
time (with any adjustments) in exchange for or otherwise with respect to the
Common Shares or Warrant Shares (including shares issued pursuant to Section 2.2
hereof).

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         1.5      "Registration Period" means the period between the date of
this Agreement and the earlier of (i) the date on which (x) all of the
Registrable Securities have been sold by the Investors pursuant to the
Registration Statement and (y) are freely tradable under the Securities Act
(except that this clause (y) shall not apply with respect to Shares sold to
affiliates) and no further Registrable Securities may be issued in the future,
(ii) the second anniversary of the last date on which Warrant Shares are
purchased under any then-outstanding Warrants, or (iii) the date on which all
the Registrable Securities may be immediately sold by the Investors without
registration and without restriction as to the number of Registrable Securities
to be sold, pursuant to Rule 144 or otherwise.

         1.6      "Registration Statement" means a Registration Statement of the
Company filed under the Securities Act.

         1.7      The terms "register," "registered," and "registration" refer
to a registration effected by preparing and filing a Registration Statement or
statements in compliance with the Securities Act and pursuant to Rule 415 and
the declaration or ordering of effectiveness of such Registration Statement by
the SEC.

         1.8      "Rule 415" means Rule 415 under the Securities Act, or any
successor Rule providing for offering securities on a continuous basis, and
applicable rules and regulations thereunder.

         1.9      "Securities" means the Common Shares and the Warrants sold
pursuant to the Purchase Agreement.

         1.10     "Warrants" means the warrants to purchase shares of the
Company's Common Stock sold pursuant to the Purchase Agreement.

         1.11     "Warrant Shares" means the shares of the Company's Common
Stock that may be purchased upon exercise of the Warrants.

                                   ARTICLE II
                                  REGISTRATION

         2.1      Mandatory Registration. The Company will use best efforts to
file with the SEC a Registration Statement on Form S-3 registering all of the
Registrable Securities for resale within 30 days after the Closing Date under
the Purchase Agreement. If Form S-3 is not available at that time, then the
Company will file a Registration Statement on such form as is then available to
effect a registration of all of the Registrable Securities, subject to the
consent of the Investors, which consent will not be unreasonably withheld.

         2.2      Effectiveness of the Registration Statement. The Company will
use its best efforts to cause the Registration Statement to be declared
effective by the SEC as soon as practicable after filing, and in any event no
later than the 90th day after the Closing Date (the "Required Effective Date").
However, so long as the Company filed the Registration Statement within 30 days
after the Closing Date, (a) if the SEC takes the position that registration of
the resale of the Registrable Securities by the Investors is not available under
applicable laws, rules and regulation and that the Company must register the
offering of the Registrable Securities as a primary offering by the Company, or
(b) if the Registration Statement receives SEC review, then the Required
Effective Date will be the 120th day after the Closing Date. In the case of an
SEC response described in clause (a),

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the Company will, within 40 business days after the date the Company receives
such SEC response, file a Registration Statement as a primary offering. The
Company's best efforts will include, but not be limited to, promptly responding
to all comments received from the staff of the SEC. If the Company receives
notification from the SEC that the Registration Statement will receive no action
or review from the SEC, then the Company will cause the Registration Statement
to become effective within five business days after such SEC notification. Once
the Registration Statement is declared effective by the SEC, the Company will
cause the Registration Statement to remain effective throughout the Registration
Period, except as permitted under Section 3. On the date of each monthly
anniversary of the date on which any breach of this Section 2.2 first occurs
(including failure to file a Registration Statement or to cause a Registration
Statement to be declared effective within the time periods set forth herein)
until the applicable default is cured (each a "Payment Date"), the Company shall
pay to each Investor as damages 1.5% of the purchase price paid by such Investor
pursuant to the Purchase Agreement. Such payment shall be the sole remedy to the
Investors for the Company's default of this Section 2.2 and shall be made in
shares of Common Stock, valued at the average closing sale prices of the
Company's Common Stock during five (5) trading days ending on the day prior to
the Payment Date, provided, that the total number of shares of the Company's
Common Stock payable pursuant to this Section 2.2 to any Investor shall not
exceed the lower of (i) the aggregate number of shares purchased pursuant to the
Purchase Agreement by such Investor and (ii) the number of shares, less one
share, which, if issued, would have, at the time of the Closing Date or the
Payment Date, required shareholder approval of such issuance pursuant to Section
4350(i)(1)(D) of the Nasdaq Marketplace Rules. In the event the number of shares
of the Company's Common Stock issuable under this Section 2.2 is restricted by
the limitations in the previous sentence, the balance of the damages payable by
the Company pursuant to this Section 2.2 shall be paid in cash on the applicable
Payment Date in accordance with payment instructions provided by each Investor.

         2.3      Piggyback Registrations.

                  (a)      If, at any time prior to the expiration of the
Registration Period, the Registration Statement contemplated in Section 2.1
above is not declared effective with respect to all of the Registrable
Securities and the Company decides to register any of its securities for its own
account or for the account of others, then the Company will promptly give the
Investors written notice thereof and will use its best efforts to include in
such registration all or any part of the Registrable Securities requested by
such Investors to be included therein (excluding any Registrable Securities
previously included in a Registration Statement which has been declared
effective and has not been withdrawn). This requirement does not apply to
Company registrations on Form S-4 or S-8 or their equivalents relating to equity
securities to be issued solely in connection with an acquisition of any entity
or business or equity securities issuable in connection with stock option or
other employee benefit plans. Each Investor must give its request for
registration under this paragraph to the Company in writing within 15 days after
receipt from the Company of notice of such pending registration. If the
registration for which the Company gives notice is a public offering involving
an underwriting, the Company will so advise the Investors as part of the
above-described written notice. In that event, if the managing underwriter(s) of
the public offering impose a limitation on the number of shares of Common Stock
that may be included in the Registration Statement because, in such
underwriter(s)' judgment, such limitation would be necessary to effect an
orderly public distribution, then the Company will be obligated to include only
such limited portion, if any, of the Registrable Securities with respect to
which such Investors have requested inclusion hereunder. Any exclusion of
Registrable Securities will be made pro rata among all holders of the Company's
securities seeking to include shares of Common Stock in proportion to the number
of shares of Common Stock

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sought to be included by those holders. However, the Company will not exclude
any Registrable Securities unless the Company has first excluded all outstanding
securities the holders of which are not entitled by right to inclusion of such
securities in such Registration Statement or are not entitled pro rata inclusion
with the Registrable Securities. No registration rights that limit or
subordinate the rights of the Investors to register the Registrable Securities
will be granted by the Company until one or more registration statements
covering all of the Registrable Securities have become effective.

                  (b)      No right to registration of Registrable Securities
under this Section 2.3 limits in any way the registration required under Section
2.1 above. The obligations of the Company under this Section 2.3 expire upon the
earlier of (i) the effectiveness of the Registration Statement filed pursuant to
Section 2.1 above, (ii) after the Company has afforded the opportunity for the
Investors to exercise registration rights under this Section 2.3 for two
registrations (provided, however, that any Investor that has had any Registrable
Securities excluded from any Registration Statement in accordance with this
Section 2.3 may include in any additional Registration Statement filed by the
Company the Registrable Securities so excluded), (iii) when all of the
Registrable Securities held by any Investor may be sold by such Investor under
Rule 144 without being subject to any volume restrictions, or (iv) the second
anniversary of the last date on which Warrant Shares are purchased under any
then outstanding Warrants.

         2.4      Eligibility to use Form S-3. The Company represents and
warrants that it meets the requirements for the use of Form S-3 for registration
of the sale by the Investors of the Registrable Securities. The Company will
file all reports required to be filed by the Company with the SEC in a timely
manner so as to preserve its eligibility for the use of Form S-3.

                                  ARTICLE III
                      ADDITIONAL OBLIGATIONS OF THE COMPANY

         3.1      Continued Effectiveness of Registration Statement. Subject to
the limitations set forth in Section 3.6, the Company will keep the Registration
Statement covering the Registrable Securities effective under Rule 415 at all
times during the Registration Period. In the event that the number of shares
available under a Registration Statement filed pursuant to this Agreement is
insufficient to cover all of the Registrable Securities issued, the Company will
(if permitted) amend the Registration Statement or file a new Registration
Statement (on the short form available therefor, if applicable), or both, so as
to cover all of the Registrable Securities. The Company will file such amendment
or new Registration Statement as soon as practicable, but in no event later than
30 business days after the necessity therefor arises (based upon the market
price of the Common Stock and other relevant factors on which the Company
reasonably elects to rely). The Company will use its best efforts to cause such
amendment or new Registration Statement to become effective as soon as is
practicable after the filing thereof, but in no event later than 90 days after
the date on which the Company reasonably first determines the need therefor.

         3.2      Accuracy of Registration Statement. Any Registration Statement
(including any amendments or supplements thereto and prospectuses contained
therein) filed by the Company covering Registrable Securities will not contain
any untrue statement of a material fact or omit to state a material fact
required to be stated therein, or necessary to make the statements therein, in
light of the circumstances in which they were made, not misleading. The Company
will prepare and file with the SEC such amendments (including post-effective
amendments) and supplements to the Registration Statement and the prospectus
used in connection with the Registration Statement as may be necessary to permit
sales pursuant to the Registration Statement at all times during the

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Registration Period, and, during such period, will comply with the provisions of
the Securities Act with respect to the disposition of all Registrable Securities
of the Company covered by the Registration Statement until the termination of
the Registration Period, or if earlier, until such time as all of such
Registrable Securities have been disposed of in accordance with the intended
methods of disposition by the seller or sellers thereof as set forth in the
Registration Statement.

         3.3      Furnishing Documentation. The Company will furnish to each
Investor whose Registrable Securities are included in a Registration Statement,
or to its legal counsel, (a) promptly after such document is filed with the SEC,
one copy of any Registration Statement filed pursuant to this Agreement and any
amendments thereto, each preliminary prospectus and final prospectus and each
amendment or supplement thereto; and (b) a number of copies of a prospectus,
including a preliminary prospectus, and all amendments and supplements thereto,
and such other documents as the Investor may reasonably request in order to
facilitate the disposition of the Registrable Securities owned by the Investor.
The Company will promptly notify by facsimile or email each Investor whose
Registrable Securities are included in any Registration Statement of the
effectiveness of the Registration Statement and any post-effective amendment.

         3.4      Additional Obligations. The Company will use its best efforts
to (a) register and qualify the Registrable Securities covered by a Registration
Statement under such other securities or blue sky laws of such jurisdictions as
each Investor who holds (or has the right to hold) Registrable Securities being
offered reasonably requests, (b) prepare and file in those jurisdictions any
amendments (including post-effective amendments) and supplements to such
registrations and qualifications as may be necessary to maintain their
effectiveness during the Registration Period, (c) take any other actions
necessary to maintain such registrations and qualifications in effect at all
times during the Registration Period, and (d) take any other actions reasonably
necessary or advisable to qualify the Registrable Securities for sale in such
jurisdictions. Notwithstanding the foregoing, the Company is not required, in
connection with such obligations, to (i) qualify to do business in any
jurisdiction where it would not otherwise be required to qualify but for this
Section 3.4, (ii) subject itself to general taxation in any such jurisdiction,
(iii) file a general consent to service of process in any such jurisdiction,
(iv) provide any undertakings that cause material expense or material burden to
the Company, or (v) make any change in its charter or bylaws, which in each case
the Board of Directors of the Company determines to be contrary to the best
interests of the Company and its stockholders.

         3.5      Underwritten Offerings. If the Investors who hold a majority
in interest of the Registrable Securities being offered in an offering pursuant
to a Registration Statement or any amendment or supplement thereto under this
Agreement select underwriters reasonably acceptable to the Company for such
offering, the Company will enter into and perform its obligations under an
underwriting agreement in usual and customary form including, without
limitation, customary indemnification and contribution obligations, with the
managing underwriter of such offering.

         3.6      Suspension of Registration.

                  (a)      The Company will notify (by telephone and also by
facsimile and reputable overnight courier) each Investor who holds Registrable
Securities being sold pursuant to a Registration Statement of the happening of
any event of which the Company has knowledge as a result of which the prospectus
included in the Registration Statement as then in effect includes an untrue
statement of a material fact or omits to state a material fact required to be
stated therein or necessary to make the statements therein, in light of the
circumstances under which they were made,

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not misleading. The Company will make such notification as promptly as
practicable (but in no event more than two business days) after the Company
becomes aware of the event, will promptly (but in no event more than ten
business days) prepare and file a supplement or amendment to the Registration
Statement to correct such untrue statement or omission, and will deliver a
number of copies of such supplement or amendment to each Investor as such
Investor may reasonably request.

                  (b)      Notwithstanding the obligations under Section 3.6(a),
if in the good faith judgment of the Company, following consultation with legal
counsel, it would be detrimental to the Company and its stockholders for resales
of Registrable Securities to be made pursuant to the Registration Statement due
to the existence of a material development or potential material development
involving the Company which the Company would be obligated to disclose in the
Registration Statement, but which disclosure would be premature or otherwise
inadvisable at such time or would reasonably be expected to have a material
adverse effect upon the Company and its stockholders, the Company will have the
right to suspend the use of the Registration Statement for a period of not more
than forty-five days, provided, however, that the Company may so defer or
suspend the use of the Registration Statement no more than one time in any
twelve-month period.

                  (c)      Subject to the Company's rights under this Section 3,
the Company will use its best efforts to prevent the issuance of any stop order
or other suspension of effectiveness of a Registration Statement and, if such an
order is issued, will use its best efforts to obtain the withdrawal of such
order at the earliest possible time and to notify each Investor that holds
Registrable Securities being sold (or, in the event of an underwritten offering,
the managing underwriters) of the issuance of such order and the resolution
thereof.

                  (d)      Notwithstanding anything to the contrary contained
herein or in the Purchase Agreement, if the use of the Registration Statement is
suspended by the Company, the Company will promptly (but in no event more than
two business days) give notice of the suspension to all Investors whose
securities are covered by the Registration Statement, and will promptly (but in
no event more than two business days) notify each such Investor as soon as the
use of the Registration Statement may be resumed. Notwithstanding anything to
the contrary contained herein or in the Purchase Agreement, the Company will
cause the Transfer Agent to deliver unlegended shares of Common Stock to a
transferee of an Investor in accordance with the terms of the Purchase Agreement
in connection with any sale of Registrable Securities with respect to which such
Investor has entered into a contract for sale prior to receipt of notice of such
suspension and for which such Investor has not yet settled, unless otherwise
prohibited by law.

         3.7      Review by the Investors. The Company will permit a single firm
f legal counsel, designated by the Investors who hold a majority in interest of
the Registrable Securities being sold pursuant to a Registration Statement
("Investor's Counsel"), to review the Registration Statement and all amendments
and supplements thereto (as well as all requests for acceleration or
effectiveness thereof) a reasonable amount of time (not to exceed seven (7)
days) prior to their filing with the SEC, and will not file any document in a
form to which such counsel reasonably objects, unless otherwise required by law
in the opinion of the Company's counsel. The sections of any such Registration
Statement including information with respect to the Investors, the Investors'
beneficial ownership of securities of the Company or the Investors' intended
method of disposition of Registrable Securities must conform to the information
provided to the Company by each of the Investors or Investors Counsel.

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         3.8      Comfort Letter; Legal Opinion. At the request of the Investors
who hold a majority in interest of the Registrable Securities being sold
pursuant to a Registration Statement, and on the date that Registrable
Securities are delivered to an underwriter for sale in connection with the
Registration Statement, the Company will furnish to the Investors and the
underwriters (i) a letter, dated such date, from the Company's independent
certified public accountants, in form and substance as is customarily given by
independent certified public accountants to underwriters in an underwritten
public offering, addressed to the underwriters; and (ii) an opinion, dated such
date, from counsel representing the Company for purposes of the Registration
Statement, in form and substance as is customarily given in an underwritten
public offering, addressed to the underwriters and Investors.

         3.9      Due Diligence; Confidentiality.

                  (a)      The Company will make available for inspection by any
Investor whose Registrable Securities are being sold pursuant to a Registration
Statement, any underwriter participating in any disposition pursuant to the
Registration Statement, and any attorney, accountant or other agent retained by
any such Investor or underwriter (collectively, the "Inspectors"), all pertinent
financial and other records, pertinent corporate documents and properties of the
Company (collectively, the "Records"), as each Inspector reasonably deems
necessary to enable the Inspector to exercise its due diligence responsibility.
The Company will cause its officers, directors and employees to supply all
information that any Inspector may reasonably request for purposes of performing
such due diligence.

                 (b)      Each Inspector will hold in confidence, and will not
make any disclosure (except to an Investor) of, any Records or other information
that the Company determines in good faith to be confidential, and of which
determination the Inspectors are so notified, unless (i) the disclosure of such
Records is necessary to avoid or correct a misstatement or omission in any
Registration Statement, (ii) the release of such Records is ordered pursuant to
a subpoena or other order from a court or government body of competent
jurisdiction, (iii) the information in such Records has been made generally
available to the public other than by disclosure in violation of this or any
other agreement (to the knowledge of the relevant Inspector), (iv) the Records
or other information was developed independently by an Inspector without breach
of this Agreement, (v) the information was known to the Inspector before receipt
of such information from the Company, or (vi) the information was disclosed to
the Inspector by a third party without restriction. The Company is not required
to disclose any confidential information in the Records to any Inspector unless
and until such Inspector has entered into a confidentiality agreement (in form
and substance reasonably satisfactory to the Company) with the Company with
respect thereto, substantially in the substance of this Section 3.9(b). Each
Investor will, upon learning that disclosure of Records containing confidential
information is sought in or by a court or governmental body of competent
jurisdiction or through other means, give prompt notice to the Company and allow
the Company, at the Company's expense, to undertake appropriate action to
prevent disclosure of, or to obtain a protective order for, the Records deemed
confidential. Nothing herein will be deemed to limit the Investor's ability to
sell Registrable Securities in a manner that is otherwise consistent with
applicable laws and regulations.

                  (c)      The Company will hold in confidence, and will not
make any disclosure of, information concerning an Investor provided to the
Company under this Agreement unless (i) disclosure of such information is
necessary to comply with federal or state securities laws, (ii) the disclosure
of such information is necessary to avoid or correct a misstatement or omission
in any Registration Statement, (iii) the release of such information is ordered
pursuant to a subpoena or

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other order from a court or governmental body of competent jurisdiction, (iv)
such information has been made generally available to the public other than by
disclosure in violation of this Agreement or any other agreement, (v) the
information was disclosed to the Company by a third party without restriction or
(vi) such Investor consents to the form and content of any such disclosure. If
the Company learns that disclosure of such information concerning an Investor is
sought in or by a court or governmental body of competent jurisdiction or
through other means, the Company will give prompt notice to such Investor prior
to making such disclosure and allow such Investor, at its expense, to undertake
appropriate action to prevent disclosure of, or to obtain a protective order
for, such information.

                  3.10     Listing. The Company will (i) cause all of the
Registrable Securities covered by each Registration Statement to be listed on
each national securities exchange on which securities of the same class or
series issued by the Company are then listed, if any, if the listing of such
Registrable Securities is then permitted under the rules of such exchange, or
(ii) to the extent the securities of the same class or series are not then
listed on a national securities exchange, secure the designation and quotation
of all of the Registrable Securities covered by each Registration Statement on
Nasdaq.

         3.11     Transfer Agent; Registrar. The Company will provide a transfer
agent and registrar, which may be a single entity, for the Registrable
Securities not later than the effective date of the Registration Statement.

         3.12     Share Certificates. The Company will cooperate with the
Investors who hold Registrable Securities being sold and with the managing
underwriter(s), if any, to facilitate the timely preparation and delivery of
certificates (not bearing any restrictive legends) representing Registrable
Securities to be offered pursuant to a Registration Statement and will enable
such certificates to be in such denominations or amounts as the case may be, and
registered in such names as the Investors or the managing underwriter(s), if
any, may reasonably request, all in accordance with Article V of the Purchase
Agreement.

         3.13     Plan of Distribution. At the request of the Investors holding
a majority in interest of the Registrable Securities registered pursuant to a
Registration Statement, the Company will promptly prepare and file with the SEC
such amendments (including post-effective amendments) and supplements to the
Registration Statement, and the prospectus used in connection with the
Registration Statement, as may be necessary in order to change the plan of
distribution set forth in such Registration Statement.

         3.14     Securities Laws Compliance. The Company will comply with all
applicable laws related to any Registration Statement relating to the offer and
sale of Registrable Securities and with all applicable rules and regulations of
governmental authorities in connection therewith (including, without limitation,
the Securities Act, the Exchange Act and the rules and regulations promulgated
by the SEC).

         3.15     Further Assurances. The Company will take all other reasonable
actions as any Investor or the underwriters, if any, may reasonably request to
expedite and facilitate disposition by such Investor of the Registrable
Securities pursuant to the Registration Statement.

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                                   ARTICLE IV
                          OBLIGATIONS OF THE INVESTORS

         4.1      Investor Information. As a condition to the obligations of the
Company to complete any registration pursuant to this Agreement with respect to
the Registrable Securities of each Investor, such Investor will furnish to the
Company such information regarding itself, the Registrable Securities held by it
and the intended method of disposition of the Registrable Securities held by it
as is reasonably required by the Company to effect the registration of the
Registrable Securities. At least 10 business days prior to the first anticipated
filing date of a Registration Statement for any registration under this
Agreement, the Company will notify each Investor of the information the Company
requires from that Investor if the Investor elects to have any of its
Registrable Securities included in the Registration Statement. If, within three
business days prior to the filing date, the Company has not received the
requested information from an Investor, then the Company may file the
Registration Statement without including Registrable Securities of that
Investor.

         4.2      Further Assurances. Each Investor will cooperate with the
Company, as reasonably requested by the Company, in connection with the
preparation and filing of any Registration Statement hereunder, unless such
Investor has notified the Company in writing of such Investor's election to
exclude all of such Investor's Registrable Securities from the Registration
Statement.

         4.3      Suspension of Sales. Upon receipt of any notice from the
Company of the happening of any event of the kind described in Section 3.6, each
Investor will immediately discontinue disposition of Registrable Securities
pursuant to the Registration Statement covering such Registrable Securities
until it receives copies of the supplemented or amended prospectus contemplated
by Section 3.6. If so directed by the Company, each Investor will deliver to the
Company (at the expense of the Company) or destroy (and deliver to the Company a
certificate of destruction) all copies in the Investor's possession (other than
a limited number of file copies) of the prospectus covering such Registrable
Securities that is current at the time of receipt of such notice.

         4.4      Underwritten Offerings.

         (a)      If Investors holding a majority in interest of the Registrable
Securities being registered (with the approval of the Initial Investors)
determine to engage the services of an underwriter, each Investor will enter
into and perform such Investor's obligations under an underwriting agreement, in
usual and customary form, including, without limitation, customary
indemnification and contribution obligations, with the managing underwriter of
such offering, and will take such other actions as are reasonably required in
order to expedite or facilitate the disposition of the Registrable Securities,
unless such Investor has notified the Company in writing of such Investor's
election to exclude all of its Registrable Securities from such Registration
Statement.

         (b)      Without limiting any Investor's rights under Section 2.1
hereof, no Investor may participate in any underwritten distribution hereunder
unless such Investor (a) agrees to sell such Investor's Registrable Securities
on the basis provided in any underwriting arrangements approved by the Investors
entitled hereunder to approve such arrangements, (b) completes and executes all
questionnaires, powers of attorney, indemnities, underwriting agreements and
other documents reasonably required under the terms of such underwriting
arrangements, and (c) agrees to pay its pro rata share of all underwriting
discounts and commissions applicable with respect to its Registrable Securities.

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                                   ARTICLE V
                            EXPENSES OF REGISTRATION

         The Company will bear all reasonable expenses, other than underwriting
discounts and commissions, and transfer taxes, if any, incurred in connection
with registrations, filings or qualifications pursuant to Articles II and III of
this Agreement, including, without limitation, all registration, listing and
qualifications fees, printers and accounting fees, the fees and disbursements of
counsel for the Company, and the reasonable fees and disbursements of one firm
of legal counsel selected by the Initial Investors pursuant to Section 3.7
hereof.

                                   ARTICLE VI
                                 INDEMNIFICATION

         In the event that any Registrable Securities are included in a
Registration Statement under this Agreement:

         6.1      To the extent permitted by law, the Company will indemnify,
defend and hold harmless each Investor that holds such Registrable Securities,
and agents, employees, attorneys, accountants, underwriters (as defined in the
Securities Act) for such Investors and any directors or officers of such
Investor or such underwriter and any person who controls such Investor or such
underwriter within the meaning of the Securities Act or the Exchange Act (each,
an "Investor Indemnified Person") against any losses, claims, damages, expenses
or liabilities (collectively, and together with actions, proceedings or
inquiries by any regulatory or self-regulatory organization, whether commenced
or threatened in respect thereof, "Claims") to which any of them become subject
under the Securities Act, the Exchange Act or otherwise, insofar as such Claims
arise out of or are based upon any of the following statements, omissions or
violations in a Registration Statement filed pursuant to this Agreement, any
post-effective amendment thereof or any prospectus included therein: (a) any
untrue statement or alleged untrue statement of a material fact contained in the
Registration Statement or any post-effective amendment thereof or the omission
or alleged omission to state therein a material fact required to be stated
therein or necessary to make the statements therein not misleading, (b) any
untrue statement or alleged untrue statement of a material fact contained in the
prospectus or any preliminary prospectus (as it may be amended or supplemented)
or the omission or alleged omission to state therein any material fact necessary
to make the statements made therein, in light of the circumstances under which
the statements therein were made, not misleading, or (c) any violation or
alleged violation by the Company of the Securities Act, the Exchange Act or any
other law, including without limitation any state securities law or any rule or
regulation thereunder (the matters in the foregoing clauses (a) through (c)
being, collectively, "Violations"). Subject to the restrictions set forth in
Section 6.4 with respect to the number of legal counsel, the Company will
reimburse the Investors and each such attorney, accountant, underwriter or
controlling person and each such other Investor Indemnified Person, promptly as
such expenses are incurred and are due and payable, for any legal fees or other
reasonable expenses incurred by them in connection with investigating or
defending any Claim. Notwithstanding anything to the contrary contained herein,
the indemnification agreement contained in this Section 6.1 (i) does not apply
to a Claim by an Investor Indemnified Person arising out of or based upon a
Violation that occurs in reliance upon and in conformity with information
furnished in writing to the Company by such Investor Indemnified Person
expressly for use in the Registration Statement or any such amendment thereof or
supplement thereto, if such prospectus or supplement thereto was timely made
available by the Company pursuant to Section 3.3 hereof; and (ii) does not apply
to amounts paid in settlement of any Claim if such settlement is made without
the prior written consent of the Company, which consent will not be unreasonably
withheld. This indemnity obligation will remain in full force

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<PAGE>

and effect regardless of any investigation made by or on behalf of the
Indemnified Persons and will survive the transfer of the Registrable Securities
by the Investors under Article IX of this Agreement.

         6.2      In connection with any Registration Statement in which an
Investor is participating, each such Investor will indemnify and hold harmless,
to the same extent and in the same manner set forth in Section 6.1 above, the
Company, each of its directors, each of its officers who signs the Registration
Statement, each person, if any, who controls the Company within the meaning of
the Securities Act or the Exchange Act, and any other stockholder selling
securities pursuant to the Registration Statement or any of its directors or
officers or any person who controls such stockholder within the meaning of the
Securities Act or the Exchange Act (each a "Company Indemnified Person") against
any Claim to which any of them may become subject under the Securities Act, the
Exchange Act or otherwise, insofar as such Claim arises out of or is based upon
any Violation, in each case to the extent (and only to the extent) that such
Violation occurs in reliance upon and in conformity with written information
furnished to the Company by such Investor expressly for use in such Registration
Statement. Subject to the restrictions set forth in Section 6.4 with respect to
the number of legal counsel, such Investor will promptly reimburse each Company
Indemnified Person for any legal or other expenses (promptly as such expenses
are incurred and due and payable) reasonably incurred by them in connection with
investigating or defending any such Claim. However, the indemnity agreement
contained in this Section 6.2 does not apply to amounts paid in settlement of
any Claim if such settlement is effected without the prior written consent of
such Investor, which consent will not be unreasonably withheld, and no Investor
will be liable under this Agreement (including this Section 6.2 and Article VII)
for the amount of any Claim that exceeds the net proceeds actually received by
such Investor as a result of the sale of Registrable Securities pursuant to such
Registration Statement. This indemnity will remain in full force and effect
regardless of any investigation made by or on behalf of a Company Indemnified
Party and will survive the transfer of the Registrable Securities by the
Investors under Article IX of this Agreement.

         6.3      If any proceeding shall be brought or asserted against any
person entitled to indemnity under Sections 6.1 or 6.2 hereof (an "Indemnified
Party"), such Indemnified Party promptly shall notify the person from whom
indemnity is sought (the "Indemnifying Party") in writing, and the Indemnifying
Party shall assume the defense thereof, including the employment of counsel
reasonably satisfactory to the Indemnified Party and the payment of all
reasonable fees and expenses incurred in connection with defense thereof;
provided, however, that the failure of any Indemnified Party to give such notice
shall not relieve the Indemnifying Party of its obligations or liabilities
pursuant to this Agreement, except (and only) to the extent that it shall be
finally determined by a court of competent jurisdiction (which determination is
not subject to appeal or further review) that such failure shall have
proximately and materially adversely prejudiced the Indemnifying Party.

         6.4      An Indemnified Party shall have the right to employ separate
counsel in any such proceeding and to participate in the defense thereof, but
the fees and expenses of such counsel shall be at the expense of such
Indemnified Party or Indemnified Parties unless: (i) the Indemnifying Party has
agreed in writing to pay such fees and expenses; (ii) the Indemnifying Party
shall have failed promptly to assume the defense of such proceeding and to
employ counsel reasonably satisfactory to such Indemnified Party in any such
proceeding; or (iii) the named parties to any such proceeding (including any
impleaded parties) include both such Indemnified Party and the Indemnifying
Party, and such Indemnified Party shall have been advised by counsel that a
conflict of interest is likely to exist if the same counsel were to represent
such Indemnified Party and the Indemnifying Party (in which case, if such
Indemnified Party notifies the Indemnifying Party in writing that it elects to

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<PAGE>

employ separate counsel at the expense of the Indemnifying Party, the
Indemnifying Party shall not have the right to assume the defense thereof and
such counsel shall be at the reasonable expense of the Indemnifying Party;
provided, however, that in no event shall the Indemnifying Party be responsible
for the fees and expenses of more than one separate counsel). The Indemnifying
Party shall not be liable for any settlement of any such proceeding effected
without its written consent, which consent shall not be unreasonably withheld.
No Indemnifying Party shall, without the prior written consent of the
Indemnified Party, effect any settlement of any pending proceeding in respect of
which any Indemnified Party is a party, unless such settlement includes an
unconditional release of such Indemnified Party from all liability on Claims
that are the subject matter of such proceeding.

         6.5      Subject to the foregoing, all reasonable fees and expenses of
the Indemnified Party (including fees and expenses to the extent incurred in
connection with investigating or preparing to defend such proceeding in a manner
not inconsistent with this Section) shall be paid to the Indemnified Party, as
incurred, within ten (10) Business Days of written notice thereof to the
Indemnifying Party, which notice shall be delivered no more frequently than on a
monthly basis (regardless of whether it is ultimately determined that an
Indemnified Party is not entitled to indemnification hereunder; provided, that
the Indemnifying Party may require such Indemnified Party to undertake to
reimburse all such fees and expenses to the extent it is finally judicially
determined that such Indemnified Party is not entitled to indemnification
hereunder).

                                  ARTICLE VII
                                  CONTRIBUTION

         To the extent that any indemnification provided for herein is
prohibited or limited by law, the indemnifying party will make the maximum
contribution with respect to any amounts for which it would otherwise be liable
under Article VI to the fullest extent permitted by law. However, (a) no
contribution will be made under circumstances where the maker would not have
been liable for indemnification under the fault standards set forth in Article
VI (without giving effect to any prohibition or limitation or indemnification
under applicable law), (b) no person guilty of fraudulent misrepresentation
(within the meaning of Section 11(f) of the Securities Act) will be entitled to
contribution from any person who was not guilty of such fraudulent
misrepresentation, and (c) contribution (together with any indemnification or
other obligations under this Agreement) by any seller of Registrable Securities
will be limited in amount to the net amount of proceeds received by such seller
from the sale of such Registrable Securities.

                                  ARTICLE VIII
                             EXCHANGE ACT REPORTING

         In order to make available to the Investors the benefits of Rule 144 or
any similar rule or regulation of the SEC that may at any time permit the
Investors to sell securities of the Company to the public without registration,
the Company will:

                  (a)      File with the SEC in a timely manner, and make and
keep available, all reports and other documents required of the Company under
the Securities Act and the Exchange Act so long as the Company remains subject
to such requirements (it being understood that nothing herein limits the
Company's obligations under Section 4.3 of the Purchase Agreement) and file and
make available of such reports and other documents as required for the
applicable provisions of Rule 144; and

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<PAGE>

                  (b)      Furnish to each Investor, so long as such Investor
holds Registrable Securities, promptly upon the Investor's request, (i) a
written statement by the Company that it has complied with the reporting
requirements of Rule 144, the Securities Act and the Exchange Act, (ii) a copy
of the most recent annual or quarterly report of the Company and such other
reports and documents filed by the Company with the SEC and (iii) such other
information as may be reasonably requested to permit the Investors to sell such
securities pursuant to Rule 144 without registration.

                                   ARTICLE IX
                        ASSIGNMENT OF REGISTRATION RIGHTS

         The rights of the Initial Investors hereunder, including the right to
have the Company register Registrable Securities pursuant to this Agreement, may
be assigned by the Initial Investors to transferees or assignees of all or any
portion of the Registrable Securities, but only if (a) the Investor agrees in
writing with the transferee or assignee to assign such rights, and a copy of
such agreement is furnished to the Company within a reasonable time after such
assignment, (b) the Company is, within a reasonable time after such transfer or
assignment, furnished with written notice of the name and address of such
transferee or assignee and the securities with respect to which such
registration rights are being transferred or assigned, (c) after such transfer
or assignment, the further disposition of such securities by the transferee or
assignee is restricted under the Securities Act and applicable state securities
laws, (d) at or before the time the Company received the written notice
contemplated by clause (b) of this sentence, the transferee or assignee agrees
in writing with the Company to be bound by all of the provisions contained
herein, (e) such transfer is made in accordance with the applicable requirements
of the Purchase Agreement, and (f) the transferee is an "accredited investor" as
that term is defined in Rule 501 of Regulation D.

                                   ARTICLE X
                        AMENDMENT OF REGISTRATION RIGHTS

         This Agreement may be amended and the obligations hereunder may be
waived (either generally or in a particular instance, and either retroactively
or prospectively) only with the written consent of the Company and of the
Investors who then hold a majority interest of the Registrable Securities. Any
amendment or waiver effected in accordance with this Article X is binding upon
each Investor and the Company.

                                   ARTICLE XI
                                  MISCELLANEOUS

         11.1     Conflicting Instructions. A person or entity is deemed to be a
holder of Registrable Securities whenever such person or entity owns of record
such Registrable Securities. If the Company receives conflicting instructions,
notices or elections from two or more persons or entities with respect to the
same Registrable Securities, the Company will act upon the basis of
instructions, notice or election received from the registered owner of such
Registrable Securities.

         11.2     Notices. Any notices required or permitted to be given under
the terms of this Agreement will be given as set forth in the Purchase
Agreement.

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<PAGE>

         11.3     Waiver. Failure of any party to exercise any right or remedy
under this Agreement or otherwise, or delay by a party in exercising such right
or remedy, does not operate as a waiver thereof.

         11.4     Governing Law. This Agreement will be governed by and
interpreted in accordance with the laws of the State of Delaware without regard
to the principles of conflict of laws. The parties hereto hereby submit to the
exclusive jurisdiction of the United States federal and state courts located in
the State of Delaware with respect to any dispute arising under this Agreement,
the agreements entered into in connection herewith or the transactions
contemplated hereby or thereby. EACH PARTY HEREBY IRREVOCABLY WAIVES ANY RIGHT
THAT IT MAY HAVE TO, AND AGREES NOT TO REQUEST, A JURY TRIAL FOR THE
ADJUDICATION OF ANY DISPUTE HEREUNDER OR IN CONNECTION HEREWITH OR WITH ANY
TRANSACTION CONTEMPLATED HEREBY.

         11.5     Severability. If any provision of this Agreement is invalid or
unenforceable under any applicable statute or rule of law, then such provision
will be deemed modified in order to conform with such statute or rule of law.
Any provision hereof that may prove invalid or unenforceable under any law will
not affect the validity or enforceability of any other provision hereof.

         11.6     Entire Agreement. This Agreement and the Purchase Agreement
(including all schedules and exhibits thereto) constitute the entire agreement
among the parties hereto with respect to the subject matter hereof and thereof.
There are no restrictions, promises, warranties or undertakings, other than
those set forth or referred to herein or therein. This Agreement supersedes all
prior agreements and understandings among the parties hereto with respect to the
subject matter hereof.

         11.7     Successors and Assigns. Subject to the requirements of Article
IX hereof, this Agreement inures to the benefit of and is binding upon the
successors and assigns of each of the parties hereto. Notwithstanding anything
to the contrary herein, including, without limitation, Article IX, the rights of
an Investor hereunder are assignable to and exercisable by a bona fide pledgee
of the Registrable Securities in connection with an Investor's margin or
brokerage accounts.

         11.8     Headings. The headings of this Agreement are for convenience
of reference only, are not part of this Agreement and do not affect its
interpretation.

         11.9     Counterparts. This Agreement may be executed in two or more
counterparts, each of which is deemed an original but all of which constitute
one and the same agreement. This Agreement, once executed by a party, may be
delivered to the other party hereto by facsimile transmission, and facsimile
signatures are binding on the parties hereto.

         11.10    Further Assurances. Each party will do and perform, or cause
to be done and performed, all such further acts and things, and will execute and
deliver all other agreements, certificates, instruments and documents, as
another party may reasonably request in order to carry out the intent and
accomplish the purposes of this Agreement and the consummation of the
transactions contemplated hereby.

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<PAGE>

         11.11    Consents. Unless otherwise provided in this Agreement, all
consents and other determinations to be made by the Investors pursuant to this
Agreement will be made by the Investors holding a majority in interest of the
Registrable Securities.

         11.12    No Strict Construction. The language used in this Agreement is
deemed to be the language chosen by the parties to express their mutual intent,
and no rules of strict construction will be applied against any party.

                                       15

<PAGE>

         IN WITNESS WHEREOF, the undersigned Investors and the Company have
caused this Registration Rights Agreement to be duly executed as of the date
first above written.

                                          COMPANY:

                                          SONUS PHARMACEUTICALS, INC.

                                          By:___________________________________
                                          Name:_________________________________
                                          Title:________________________________

                                       16

<PAGE>

                            OMNIBUS SIGNATURE PAGE TO
                           SONUS PHARMACEUTICALS, INC.
                          REGISTRATION RIGHTS AGREEMENT

         The undersigned hereby executes and delivers the Registration Rights
Agreement to which this Signature Page is attached, which, together with all
counterparts of the Agreement and Signature Pages of the other parties named in
said Agreement, shall constitute one and the same document in accordance with
the terms of the Agreement.

                                              Sign Name:________________________
                                              Print Name:_______________________
                                              Address:__________________________
                                                      __________________________
                                                      __________________________

                                              Telephone: _______________________
                                              Facsimile:________________________

                                              Number of Common Shares:__________
                                              Number of Warrant Shares:_________

                                       17