Document:

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                                                                    EXHIBIT 10.4

                      CHANGE OF CONTROL/SEVERANCE AGREEMENT

      This CHANGE OF CONTROL/SEVERANCE AGREEMENT, dated as of December 16, 2005
by and between PAREXEL International Corporation (together with all subsidiaries
or affiliates hereinafter referred to as the "Company") and Mark A. Goldberg
(the "Executive").

      WHEREAS, the Executive has been hired as a senior executive of the Company
and is expected to make major contributions to the Company;

      WHEREAS, the Company desires continuity of management; and

      WHEREAS, the Executive is willing to render services to the Company
subject to the conditions set forth in this Agreement.

      NOW, THEREFORE, for good and valuable consideration, the receipt and
sufficiency of which is hereby acknowledged, the Company and the Executive agree
as follows:

      1.    TERMINATION WITHOUT CAUSE.

      In the event the Company terminates the Executive's employment with the
Company without Cause (as such term is defined in Section 4(c) below), the
Company shall pay to the Executive lump sum amounts (net of any required
withholding) equal to (i) twelve (12) months of monthly base salary (at the
highest monthly base salary rate in effect for the Executive in the twelve month
period prior to the termination of his employment)("Base Salary")(which shall be
paid within ten business days following the Executive's last date of
employment), plus (ii) the pro rata share of the bonus that would otherwise have
been payable to the Executive pursuant to the Company's Performance Bonus Plan
(the "PBP") during the year in which the termination occurs had his employment
not been terminated by the Company, based on bonus arrangements in effect at any
time during the twelve month period immediately prior to the termination of his
employment, such pro rata share to be calculated from the beginning of the
fiscal year in which the termination occurs through the date of termination
(which shall be paid within ten business days after the payment of bonuses, if
any, to the Company's executive officers pursuant to the PBP for the year in
which the termination occurred); provided, however, that such pro rata bonus
shall only be payable to the extent of, and in accordance with, (i) the
Company's determination that the Company's and the Executive's PBP performance
goals have been satisfied, and (ii) the Company's determination to pay bonuses
to its executive officers, for the year in which the termination occurs.

      2.    TERMINATION PRIOR TO A CHANGE OF CONTROL.

      (a) Notwithstanding the provisions of Section 1 above, if, within nine
months prior to a Change of Control (as such term is defined in Section 4(b)
below) and subsequent to the

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commencement of substantive discussions that ultimately result in the Change of
Control, the Company terminates the Executive's employment with the Company
without Cause (as such term is defined in Section 4(c) below), the Company
shall:

            (1)   Pay to the Executive, within ten (10) business days following
                  the Change of Control, a lump sum amount (net of any required
                  withholding) equal to: (i) twelve (12) months of Base Salary,
                  plus (ii) the target bonus that could have been payable to the
                  Executive (assuming continued employment) during the year in
                  which the termination of employment occurs based on bonus
                  arrangements in effect at any time during the twelve month
                  period immediately prior to the termination of his employment;
                  and

            (2)   Provide the Executive and his dependents with life, accident,
                  health and dental insurance substantially similar to that
                  which the Executive was receiving immediately prior to the
                  termination of his employment until the earlier of: (i) the
                  date which is twelve (12) months following the Change of
                  Control; or (ii) the date the Executive commences subsequent
                  employment; and

            (3)   On the Change of Control, cause any unexercisable installments
                  of any stock options of the Company or any subsidiary or
                  affiliate of the Company held by the Executive on the
                  Executive's last date of employment with the Company that have
                  not expired to become exercisable on the Change of Control;
                  provided, however, that: (i) such acceleration of
                  exercisability shall not occur as to any option if the Change
                  of Control does not occur within the period within which the
                  Executive may exercise such option after a termination of
                  employment in accordance with the provisions of the relevant
                  option agreement and option plan; and (ii) any such
                  acceleration of exercisability shall not extend the period
                  after a termination of employment within which any option may
                  be exercised by the Executive in accordance with the
                  provisions of the relevant option agreement and option plan;
                  and

            (4)   On the Change of Control, cause any unvested portion of any
                  qualified or non-qualified capital accumulation benefits to
                  become immediately vested (subject to applicable law);

provided, however, that any amounts and benefits set forth in this Section 2
shall be reduced by any and all other severance or other amounts or benefits
paid or payable to the Executive as a result of the termination of his or her
employment.

      3.    TERMINATION FOLLOWING A CHANGE OF CONTROL.

      (a) Notwithstanding the provisions of Section 1 above, if, at any time
during a period commencing with a Change of Control and ending eighteen months
after such Change of Control

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the Company terminates the Executive's employment without Cause (as such term is
defined in Section 4(c) below) or the Executive terminates his employment with
the Company for Good Reason (as such term is defined in Section 3(b) below)
(provided, however, that any such termination by the Executive must occur
promptly (and in any event within 90 days) after the occurrence of the event or
events constituting "Good Reason"), the Company shall:

            (1)   Pay to the Executive, within ten (10) business days following
                  the Executive's last date of employment, a lump sum amount
                  (net of any required withholding) equal to: (i) twelve (12)
                  months of Base Salary, plus (ii) the target bonus that could
                  have been payable to such Executive (assuming continued
                  employment) during the year in which the termination of
                  employment occurs based on bonus arrangements in effect
                  immediately prior to the termination of his or her employment
                  (all payments under Sections 1, 2 and this Section 3(a) being
                  referred to collectively, as the "Severance Payments"); and

            (2)   Provide the Executive and his dependents with life, accident,
                  health and dental insurance substantially similar to that
                  which the Executive was receiving immediately prior to the
                  termination of his employment until the earlier of: (i) the
                  date which is twelve (12) months following the Executive's
                  last day of employment; or (ii) the date the Executive
                  commences subsequent employment; and

            (3)   Cause any unexercisable installments of any stock options of
                  the Company or any subsidiary or affiliate of the Company held
                  by the Executive on the Executive's last date of employment
                  with the Company that have not expired to become exercisable
                  on such last date of employment; provided, however, that: (i)
                  such acceleration of exercisability shall not occur as to any
                  option if the Change of Control does not occur within the
                  period within which the Executive may exercise such option
                  after a termination of employment in accordance with the
                  provisions of the relevant option agreement and option plan;
                  and (ii) any such acceleration of exercisability shall not
                  extend the period after a termination of employment within
                  which any option may be exercised by the Executive in
                  accordance with the provisions of the relevant option
                  agreement and option plan; and

            (4)   Cause any unvested portion of any qualified and non-qualified
                  capital accumulation benefits to become immediately vested,
                  subject to applicable law;

provided, however, that any amounts and benefits set forth in this Section 3
shall be reduced by any and all other severance or other amounts or benefits
paid or payable to the Executive as a result of the termination of his or her
employment.

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      (b) For purposes of Section 3 above, "Good Reason" shall mean the
occurrence of one or more of the following events following a Change of Control,
as the case may be: (i) the assignment to the Executive of any duties
inconsistent in any adverse, material respect with his position, authority,
duties or responsibilities immediately prior to the Change of Control or any
other action by the Company which results in a material diminution in such
position, authority, duties or responsibilities; (ii) a material reduction in
the aggregate of the Executive's base or incentive compensation or the
termination of the Executive's rights to any employee benefits immediately prior
to the Change of Control, except to the extent any such benefit is replaced with
a comparable benefit, or a reduction in scope or value thereof; or (iii) a
relocation of the Executive's place of business which results in the one-way
commuting distance for the Executive increasing by more than 25 miles from the
location thereof immediately prior to the Change of Control (provided, however,
that travel consistent with past practices for business purposes shall not be
considered "commuting" for purposes of this clause (iii)) or (iv) a failure by
the Company to obtain the agreement referenced in Section 4(f).

      4.    GENERAL.

      (a) In the event the Executive's employment with the Company is
terminated(i) by the Company at any time for Cause (as such term is defined in
Section 4(c) below), or (ii) the Executive terminates his employment with the
Company other than during the specific time periods set forth in Section 3 or
for any reason other than Good Reason (as such term is defined in Section 3(b)
above), the Executive shall not be entitled to the severance benefits or other
considerations described herein by virtue of this Agreement.

      (b) For purposes of this Agreement, "Change of Control" shall mean the
closing of: (i) a merger, consolidation, liquidation or reorganization of the
Company into or with another Company or other legal person, after which merger,
consolidation, liquidation or reorganization the capital stock of the Company
outstanding prior to consummation of the transaction is not converted into or
exchanged for or does not represent more than 50% of the aggregate voting power
of the surviving or resulting entity; (ii) the direct or indirect acquisition by
any person (as the term "person" is used in Section 13(d)(3) or 14(d)(2) of the
Securities Exchange Act of 1934, as amended) of more than 50% of the voting
capital stock of the Company, in a single or series of related transactions; or
(iii) the sale, exchange, or transfer of all or substantially all of the
Company's assets (other than a sale, exchange or transfer to one or more
entities where the stockholders of the Company immediately before such sale,
exchange or transfer retain, directly or indirectly, at least a majority of the
beneficial interest in the voting stock of the entities to which the assets were
transferred).

      (c) For purposes of this Agreement, "Cause" shall mean: (i) the commission
by the Executive of a felony, either in connection with the performance of his
obligations to the Company or which adversely affects the Executive's ability to
perform such obligations; (ii) gross negligence, breach of fiduciary duty or
breach of any confidentiality, non-competition or developments agreement in
favor of the Company; or (iii) the commission by the Executive of an act of
fraud or embezzlement or other acts in intentional disregard of the Company
which result in loss, damage or injury to the Company, whether directly or
indirectly.

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      (d) Notwithstanding anything to the contrary in this Agreement, if any
portion of any payments received by the Executive from the Company (whether
payable pursuant to the terms of this Agreement or any other plan, agreement or
arrangement with the Company, its successors or any person whose actions result
in a change of control of the Company) shall be subject to tax imposed by
Section 4999 of the Internal Revenue Code of 1986, as amended or any successor
statutory provision, the Company shall pay to the Executive such additional
amounts as are necessary so that, after taking into account any tax imposed by
Section 4999 (or any successor statutory provision), and any federal and state
income taxes payable on any such tax, the Executive is in the same after-tax
position that he or she would have been if such Section 4999 (or any successor
statutory provision) did not apply and no payments were made pursuant to this
Section 4(d). The Executive and the Company shall each reasonably cooperate with
the other in connection with any administrative or judicial proceedings
concerning the existence or amount of liability for Excise Tax with respect to
the Payments. All determinations required to be made under this Section 4(d),
including whether a Gross-Up Payment is required and the amount of such Gross-Up
Payment, shall be made by the Company, after consultation with its tax and
accounting advisors.

      (e) The parties hereto expressly agree that the payments by the Company to
the Executive in accordance with the terms of this Agreement will be liquidated
damages, and that the Executive shall not be required to mitigate the amount of
any payment provided for in this Agreement by seeking other employment or
otherwise, nor shall any profits, income, earnings or other benefits from any
source whatsoever create any mitigation, offset, reduction or any other
obligation on the part of the Executive.

      (f) Except as otherwise provided herein, this Agreement shall be binding
upon and inure to the benefit of the Company and any successor (whether direct
or indirect, by purchase, merger, consolidation, reorganization or otherwise) of
the Company; provided, however, that as a condition of closing any transaction
which results in a Change of Control, the Company shall obtain the written
agreement of any successor (whether direct or indirect, by purchase, merger,
consolidation, reorganization or otherwise) of the Company to be bound by the
provisions of this Agreement as if such successor were the Company and for
purposes of this Agreement, any such successor of the Company shall be deemed to
be the "Company" for all purposes.

      (g) Nothing in this Agreement shall create any obligation on the part of
the Company or any other person to continue the employment of the Executive. If
the Executive elects to receive the severance and benefits set forth in Sections
1, 2 or 3, the Executive shall not be entitled to any other salary continuation
or severance benefits in the event of his cessation of employment with the
Company.

      (h) Nothing herein shall affect the Executive's obligations under any key
employee, non-competition, confidentiality, option or similar agreement between
the Company and the Executive currently in effect or which may be entered into
in the future.

      (i) The Executive agrees that it will execute and deliver to the Company a
copy of the Agreement/Waiver in the form attached hereto as Exhibit A in
consideration of, and prior to the Company's payment of, any amounts payable
hereunder.

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      (j) This Agreement shall be governed by and construed in accordance with
the laws of the Commonwealth of Massachusetts. This Agreement constitutes the
entire Agreement between the Executive and the Company concerning the subject
matter hereof and supersedes any prior negotiations, understandings or
agreements concerning the subject matter hereof, whether oral or written, and
may be amended or rescinded only upon the written consent of the Company and the
Executive. The invalidity or unenforceability of any provision of this Agreement
shall not affect the other provisions of this Agreement and this Agreement shall
be construed and reformed to the fullest extent possible. The Executive may not
assign any of his rights or obligations under this Agreement; the rights and
obligations of the Company under this Agreement shall inure to the benefit of,
and shall be binding upon, the successors and assigns of the Company. This
Agreement may be executed in any number of counterparts, all of which taken
together shall constitute one and the same instrument.

      IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be
executed as of the date first written above.

                                    The Company:

                                    PAREXEL INTERNATIONAL CORPORATION

                                    By: /s/ Josef H. von Rickenbach
                                        ----------------------------------------

                                    Name: Josef H. von Rickenbach

                                    Title: Chairman and Chief Executive Officer

                                    The Executive:

                                    Signature: /s/ Mark A. Goldberg
                                               ---------------------------------

                                    Printed Name: Mark A. Goldberg

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                                                                       EXHIBIT A

                                AGREEMENT/WAIVER

      It is hereby agreed by and between Mark A. Goldberg (the "Executive") and
PAREXEL International Corporation (together with all subsidiaries and affiliates
hereinafter referred to as the "Company"), for good and sufficient consideration
more fully described below, that:

      1. Consideration. The Company will provide the Executive with the amounts
and benefits described in Sections 1, 2 and 3 of the Change of Control/Severance
Agreement entered into by the Company and the Executive, dated December 16,
2005, (the "Agreement"), subject to the terms and conditions of such Agreement.
The Executive understands that payment of and all such amounts and benefits are
conditioned upon the Executive signing this agreement.

      2. Settlement of Amounts Due the Executive. The Executive agrees that the
amounts set forth above in Section 1, together with any amounts previously
provided to the Executive by the Company, shall be complete and unconditional
payment, settlement, satisfaction and accord with respect to all obligations and
liabilities of the Company and any of its affiliated companies (including their
respective successors, assigns, shareholders, officers, directors, employees
and/or agents) to the Executive, and all claims, causes of action and damages by
the Executive against the Company and/or any such other parties regarding the
Executive's employment with and termination from employment with the Company,
including, without limitation, all claims for back wages, salary, draws,
commissions, bonuses, vacation pay, equity compensation, expenses, compensation,
severance pay, attorney's fees, compensatory damages, exemplary damages, or
other costs or sums. Notwithstanding the foregoing, nothing herein shall relieve
the Company of its obligations to pay the Executive the special cash
compensation of $500,000.00, payable on or around August 22, 2006, awarded in
connection with the purchase by the Company of all minority interests in
Perceptive Informatics, Inc.

      3. Release.

      (a) In exchange for the amounts and benefits described in Section 1 above
and other good and valuable consideration, receipt of which is hereby
acknowledged, the Executive and his representatives, agents, estate, successors
and assigns, absolutely and unconditionally hereby release and forever discharge
the Company, its affiliated companies and/or their successors, assigns,
directors, shareholders, officers, employees and/or agents, both individually
and in their official capacities, (the "Releasees"), from any and all actions or
causes of action, suits, claims, complaints, contracts, liabilities, agreements,
promises, debts and damages, controversies, judgments, rights and demands,
whether existing or contingent, known or unknown, which arise under the
Agreement. This release is intended by the Executive to be all encompassing and
to act as a full and total release of any claims that the Executive may have or
has had against the Releasees under the Agreement, including, but not limited
to, any federal, state or local law or regulation dealing with either employment
or employment discrimination such as those laws or regulations concerning
discrimination on the basis of age, race, color, religion, creed, sex, sexual-

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orientation, national origin, ancestry, marital status, physical or mental
disability, any veteran status or any military service or application for any
military service; any contract, whether oral or written, express or implied; or
common law.

      (b) The Executive agrees not only to release and discharge the Releasees
from any and all claims as stated above that the Executive could make on his/her
own behalf or on behalf of others, but also those claims which might be made by
any other person or organization on behalf of the Executive, and the Executive
specifically waives any right to become, and promises not to become, a member of
any class in a case in which a claim or claims against the Releasees are made
involving any matters which arise out of, or in connection with, the Agreement.
Nothing in this agreement is to be construed as an admission by the Releasees of
any liability or unlawful conduct whatsoever.

      4. Waiver of Rights and Claims Under the Age Discrimination and Employment
Act of 1967.

      (a) The Executive has been informed that since he is 40 years of age or
older, he has or might have specific rights and/or claims under the Age
Discrimination and Employment Act of 1967. In consideration for the amounts
described in Section 1 hereof, the Executive specifically waives such rights
and/or claims to the extent that such rights and/or claims arose prior to the
date this Agreement was executed.

      (b) The Executive was advised by the Company of his right to consult with
an attorney prior to executing this Agreement.

      (c) The Executive was further advised when he was presented by the Company
with the original draft of this Agreement on _______, 200_, that he had at least
21 days within which to consider its terms and to consult with or seek advice
from an attorney or any other person of his/her choosing, until the close of
business on __________, 200_.

      5. Confidentiality. The Executive agrees he shall not divulge or publish,
directly or indirectly, any information whatsoever regarding the substance,
terms or existence of the Agreement or this agreement and/or any discussions or
negotiations relating to the Agreement or this agreement to any person or
organization, except to his immediate family members, counsel or accountant, and
unless required under law or court order.

      6. Representations and Governing Law.

      (a) This agreement represents the complete and sole understanding between
the parties regarding the subject matter hereto. This agreement may not be
modified, altered or rescinded except upon written consent of the Company and
Executive. The invalidity or unenforceability of any provision of this agreement
shall not affect the other provisions of this agreement, but this agreement
shall be revised, construed and reformed to the fullest extent possible to
effectuate the purposes of this agreement. This agreement shall be binding upon
and inure to the benefit of the Company and the Executive and their respective
heirs, successors and assigns. The parties agree

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that the Company will not have an adequate remedy if the Executive fails to
comply with Sections 3, 4, and 5 hereof and that damages will not be readily
ascertainable, and that in the event of such failure, the Executive shall not
oppose any application by the Company requiring a decree of specific performance
or an injunction enjoining a breach of this agreement. If the Executive breaches
any of his/her obligations hereunder, he shall forfeit all right to payments
pursuant to Section 1.

      (b) This agreement shall be governed by and construed in accordance with
the laws of the Commonwealth of Massachusetts, without giving effect to the
principles of conflicts of law thereof.

      (c) The Executive represents that he has read this agreement, fully
understands the terms and conditions of such agreement, and is voluntarily
executing the same. In entering into this agreement, the Executive does not rely
on any representation, promise or inducement made by the Releasees, with the
exception of the consideration described in this document.

      7. Effective Date. The Executive may revoke this agreement during the
period of seven (7) days following its execution by the Executive, and this
agreement shall not become effective or enforceable until this revocation period
has expired.

                                               The Company:

                                               PAREXEL INTERNATIONAL CORPORATION

                                               By:
                                                   _____________________________

                                               Name:
                                                     ___________________________

                                               Title:
                                                      __________________________

                                               Date:
                                                     ___________________________

                                               The Executive:

                                               Signature:
                                                         ______________________

                                               Printed Name: Mark A. Goldberg

                                               Date:
                                                     ___________________________

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                                                                    EXHIBIT 10.5

                 AMENDMENT NO. 1 TO CHANGE OF CONTROL/SEVERANCE
                                   AGREEMENT

      This AMENDMENT NO. 1 TO CHANGE OF CONTROL/SEVERANCE AGREEMENT, dated as of
February 7, 2006 by and between PAREXEL International Corporation (together with
all subsidiaries or affiliates hereinafter referred to as the "Company") and
James F. Winschel, Jr. (the "Executive").

      WHEREAS, the Executive and the Company are parties to a Change of
Control/Severance Agreement (the "Agreement"), dated as of April 3, 2001; and

      WHEREAS, the Executive and the Company desire to amend the Agreement as
set forth herein.

      NOW, THEREFORE, for good and valuable consideration, the receipt and
sufficiency of which is hereby acknowledged, the Company and the Executive agree
as follows:

      1. Section 2(a)(4) of the Agreement is hereby amended and restated in its
entirety to read as follows:

      "(4)  On the Change of Control, cause any unvested portion of any
            qualified or non-qualified capital accumulation benefits, and any
            unvested portion of any qualified or non-qualified awards made
            pursuant to any stock incentive plans, including, but not limited
            to, restricted stock units, restricted stock, stock appreciation
            rights and all other equity based awards (but excluding stock
            options), to become immediately vested (subject to applicable law)."

      2. Section 3(a)(4) of the Agreement is hereby amended and restated in its
entirety to read as follows:

      "(4)  Cause any unvested portion of any qualified or non-qualified capital
            accumulation benefits, and any portion of any qualified or
            non-qualified awards made pursuant to any stock incentive plans,
            including, but not limited to, restricted stock units, restricted
            stock, stock appreciation rights and all other equity based awards
            (but excluding stock options), to become immediately vested (subject
            to applicable law)."

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      3. All other terms and conditions of the Agreement not otherwise amended
herein shall remain in full force and effect.

      IN WITNESS WHEREOF, the parties hereto have caused this Amendment No. 1 to
be executed as of the date first written above.

                                           The Company:

                                           PAREXEL INTERNATIONAL CORPORATION

                                           By: /s/ Josef H. von Rickenbach
                                              ----------------------------------

                                           Name: Josef H. von Rickenbach

                                           Title: Chairman and CEO

                                           The Executive:

                                           Signature: /s/ James F. Winschel, Jr.
                                                     ---------------------------

                                           Printed Name: James F. Winschel, Jr.

                                       2

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