UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D. C. 20549


                                    FORM 10-Q


                Quarterly Report Pursuant to Section 13 or 15(d)
                     of the Securities Exchange Act of 1934


                For the quarterly period ended September 30, 2000


                         Commission File No. 33-26097-08


                        PARKER & PARSLEY 90-B CONV., L.P.
                       -----------------------------------
             (Exact name of Registrant as specified in its charter)


                           Delaware                           75-2329284
           ----------------------------------------     ---------------------
               (State or other jurisdiction of            (I.R.S. Employer
                incorporation or organization)          Identification Number)


1400 Williams Square West, 5205 N. O'Connor Blvd., Irving, Texas       75039
----------------------------------------------------------------     ---------
           (Address of principal executive offices)                  (Zip code)

       Registrant's Telephone Number, including area code : (972) 444-9001


       Not applicable (Former name, former address and former fiscal year,
                          if changed since last report)

Indicate by check mark whether the Registrant (1) has filed all reports required
to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during
the  preceding 12 months (or for such  shorter  period that the  Registrant  was
required  to file  such  reports),  and  (2) has  been  subject  to such  filing
requirements for the past 90 days.

                                Yes / x / No / /





<PAGE>



                        PARKER & PARSLEY 90-B CONV., L.P.

                                TABLE OF CONTENTS


                                                                       Page
                          Part I. Financial Information

Item 1.    Financial Statements

           Balance Sheets as of September 30, 2000 and
              December 31, 1999......................................    3

           Statements of Operations for the three and nine
             months ended September 30, 2000 and 1999................    4

           Statement of Partners' Capital for the nine months
             ended September 30, 2000................................    5

           Statements of Cash Flows for the nine months ended
             September 30, 2000 and 1999.............................    6

           Notes to Financial Statements.............................    7

Item 2.    Management's Discussion and Analysis of Financial
             Condition and Results of Operations.....................    7


                           Part II. Other Information

Item 6.    Exhibits and Reports on Form 8-K..........................   10

           27.1   Financial Data Schedule

           Signatures................................................   11


                                        2

<PAGE>



                        PARKER & PARSLEY 90-B CONV., L.P.
                        (A Delaware Limited Partnership)

                          Part I. Financial Information

Item 1.      Financial Statements
<TABLE>

                                 BALANCE SHEETS
<CAPTION>
                                                   September 30,   December 31,
                                                       2000            1999
                                                   ------------    -----------
                                                   (Unaudited)
                 ASSETS
<S>                                                <C>             <C>

Current assets:
  Cash                                             $   146,642     $   132,031
  Accounts receivable - oil and gas sales              191,194         143,411
                                                    ----------      ----------
           Total current assets                        337,836         275,442
                                                    ----------      ----------
Oil and gas properties - at cost,  based on the
  successful efforts accounting method               9,627,030       9,612,816
Accumulated depletion                               (8,016,553)     (7,939,049)
                                                    ----------      ----------
           Net oil and gas properties                1,610,477       1,673,767
                                                    ----------      ----------
                                                   $ 1,948,313     $ 1,949,209
                                                    ==========      ==========
LIABILITIES AND PARTNERS' CAPITAL

Current liabilities:
  Accounts payable - affiliate                     $    44,378     $    24,507

Partners' capital:
  Managing general partner                              19,038          19,246
  Limited partners (11,897 interests)                1,884,897       1,905,456
                                                    ----------      ----------
                                                     1,903,935       1,924,702
                                                    ----------      ----------
                                                   $ 1,948,313     $ 1,949,209
                                                    ==========      ==========
</TABLE>



The financial information included as of September 30, 2000 has been prepared by
 the managing general partner without audit by independent public accountants.

   The accompanying notes are an integral part of these financial statements.

                                        3

<PAGE>



                        PARKER & PARSLEY 90-B CONV., L.P.
                        (A Delaware Limited Partnership)

                            STATEMENTS OF OPERATIONS
                                   (Unaudited)



<TABLE>
<CAPTION>

                                     Three months ended         Nine months ended
                                        September 30,              September 30,
                                  -----------------------    -----------------------
                                     2000         1999          2000         1999
                                  ----------   ----------    ----------   ----------
<S>                               <C>          <C>           <C>          <C>
Revenues:
  Oil and gas                     $  405,161   $  255,759    $1,092,350   $  605,410
  Interest                             3,426        1,627         8,203        3,526
  Gain on disposition of assets          -            -           2,023          -
                                   ---------    ---------     ---------    ---------
                                     408,587      257,386     1,102,576      608,936
                                   ---------    ---------     ---------    ---------
Costs and expenses:
  Oil and gas production             135,775      115,396       413,083      352,051
  General and administrative          13,970       10,343        35,694       22,588
  Depletion                           24,992       27,690        77,504      118,619
                                   ---------    ---------     ---------    ---------
                                     174,737      153,429       526,281      493,258
                                   ---------    ---------     ---------    ---------
Net income                        $  233,850   $  103,957    $  576,295   $  115,678
                                   =========    =========     =========    =========
Allocation of net income:
  Managing general partner        $    2,339   $    1,040    $    5,763   $    1,157
                                   =========    =========     =========    =========
  Limited partners                $  231,511   $  102,917    $  570,532   $  114,521
                                   =========    =========     =========    =========
Net income per limited
  partnership interest            $    19.46   $     8.65    $    47.96   $     9.63
                                   =========    =========     =========    =========
</TABLE>



         The financial information included herein has been prepared by
  the managing general partner without audit by independent public accountants.

   The accompanying notes are an integral part of these financial statements.

                                        4

<PAGE>



                        PARKER & PARSLEY 90-B CONV., L.P.
                        (A Delaware Limited Partnership)

                         STATEMENT OF PARTNERS' CAPITAL
                                   (Unaudited)



<TABLE>
<CAPTION>

                                     Managing
                                     general        Limited
                                     partner        partners       Total
                                    -----------    ----------    ----------
<S>                                 <C>            <C>           <C>


Balance at January 1, 2000          $   19,246     $1,905,456    $1,924,702

    Distributions                       (5,971)      (591,091)     (597,062)

    Net income                           5,763        570,532       576,295
                                     ---------      ---------     ---------

Balance at September 30, 2000       $   19,038     $1,884,897    $1,903,935
                                     =========      =========     =========

</TABLE>





         The financial information included herein has been prepared by
  the managing general partner without audit by independent public accountants.

   The accompanying notes are an integral part of these financial statements.

                                        5

<PAGE>



                        PARKER & PARSLEY 90-B CONV., L.P.
                        (A Delaware Limited Partnership)

                            STATEMENTS OF CASH FLOWS
                                   (Unaudited)


<TABLE>
<CAPTION>

                                                         Nine months ended
                                                            September 30,
                                                      ------------------------
                                                         2000          1999
                                                      ----------    ----------
<S>                                                   <C>           <C>
Cash flows from operating activities:
   Net income                                         $  576,295    $  115,678
   Adjustments to reconcile net income to net
      cash provided by operating activities:
        Depletion                                         77,504       118,619
        Gain on disposition of assets                     (2,023)          -
   Changes in assets and liabilities:
        Accounts receivable                              (47,783)      (61,284)
        Accounts payable                                  19,871        14,549
                                                       ---------     ---------
          Net cash provided by operating activities      623,864       187,562
                                                       ---------     ---------
Cash flows from investing activities:
   Additions to oil and gas properties                   (14,214)       (9,417)
   Proceeds from asset dispositions                        2,023           -
                                                       ---------     ---------
          Net cash used in investing activities          (12,191)       (9,417)
                                                       ---------     ---------
Cash flows used in financing activities:
   Cash distributions to partners                       (597,062)     (136,608)
                                                       ---------     ---------
Net increase in cash                                      14,611        41,537
Cash at beginning of period                              132,031        76,330
                                                       ---------     ---------
Cash at end of period                                 $  146,642    $  117,867
                                                       =========     =========
</TABLE>



         The financial information included herein has been prepared by
  the managing general partner without audit by independent public accountants.

   The accompanying notes are an integral part of these financial statements.

                                        6

<PAGE>



                        PARKER & PARSLEY 90-B CONV., L.P.
                        (A Delaware Limited Partnership)

                          NOTES TO FINANCIAL STATEMENTS
                               September 30, 2000
                                   (Unaudited)

Note 1.     Organization and nature of operations

Parker & Parsley 90-B Conv., L.P. (the "Partnership") was organized as a general
partnership  in 1990 under the laws of the State of Texas and was converted to a
Delaware limited partnership on August 1, 1991.

The  Partnership  engages in oil and gas development and production in Texas and
is not involved in any industry segment other than oil and gas.

Note 2.     Basis of presentation

In  the  opinion  of  management,  the  unaudited  financial  statements  of the
Partnership  as of  September  30, 2000 and for the three and nine months  ended
September 30, 2000 and 1999 include all adjustments and accruals consisting only
of  normal  recurring  accrual  adjustments  which  are  necessary  for  a  fair
presentation  of the results for the interim  period.  These interim results are
not necessarily indicative of results for a full year. Certain reclassifications
may have been made to the September 30, 1999 financial  statements to conform to
the September 30, 2000 financial statement presentations.

Certain  information  and footnote  disclosures  normally  included in financial
statements prepared in accordance with generally accepted accounting  principles
have been  condensed  or omitted in this Form 10-Q  pursuant  to the results and
regulations of the Securities and Exchange Commission.  The financial statements
should  be read in  conjunction  with the  financial  statements  and the  notes
thereto  contained in the  Partnership's  Report on Form 10-K for the year ended
December 31, 1999, as filed with the Securities and Exchange Commission,  a copy
of which is available upon request by writing to Rich Dealy,  Vice President and
Chief Accounting Officer,  5205 North O'Connor  Boulevard,  1400 Williams Square
West, Irving, Texas 75039-3746.

Item 2.     Management's Discussion and Analysis of Financial Condition
              and Results of Operations (1)

Results of Operations

Nine months ended  September 30, 2000 compared with nine months ended  September
   30, 1999

Revenues:

The Partnership's oil and gas revenues  increased 80% to $1,092,350 for the nine
months ended  September  30, 2000 as compared to $605,410 for the same period in
1999.  The increase in revenues  resulted from  higher average  prices received,

                                        7

<PAGE>



offset by a decline in production. For the nine months ended September 30, 2000,
27,178 barrels of oil, 12,971 barrels of natural gas liquids ("NGLs") and 50,036
mcf of gas were sold, or 48,488 barrel of oil equivalents ("BOEs"). For the nine
months ended  September 30, 1999,  27,016 barrels of oil, 13,167 barrels of NGLs
and 54,094 mcf of gas were sold, or 49,199 BOEs.

The average  price  received per barrel of oil  increased  $13.44,  or 88%, from
$15.24  for the nine  months  ended  September  30,  1999 to $28.68 for the same
period in 2000. The average price  received per barrel of NGLs increased  $6.33,
or 76%, from $8.33 during the nine months ended September 30, 1999 to $14.66 for
the same period in 2000. The average price received per mcf of gas increased 58%
from $1.55 for the nine months  ended  September  30, 1999 to $2.45 for the same
period in 2000. The market price for oil and gas has been extremely  volatile in
the past  decade  and  management  expects a certain  amount  of  volatility  to
continue in the  foreseeable  future.  The  Partnership  may therefore  sell its
future  oil and gas  production  at  average  prices  lower or higher  than that
received during the nine months ended September 30, 2000.

A gain on disposition of assets of $2,023 was recognized  during the nine months
ended September 30, 2000 from the sale of equipment on one well.

Costs and Expenses:

Total  costs and  expenses  increased  to  $526,281  for the nine  months  ended
September  30,  2000 as compared  to  $493,258  for the same period in 1999,  an
increase of $33,023,  or 7%. The increase  was due to  increases  in  production
costs and general and  administrative  expenses ("G&A"),  offset by a decline in
depletion.

Production  costs were $413,083 for the nine months ended September 30, 2000 and
$352,051 for the same period in 1999,  resulting in a $61,032 increase,  or 17%.
The increase was primarily due to higher production taxes of $36,335  associated
with higher oil and gas prices and additional well maintenance costs incurred to
stimulate well production of $18,599.

G&A's  components are independent  accounting and engineering  fees and managing
general  partner  personnel  and  operating  costs.   During  this  period,  G&A
increased,  in aggregate,  58% from $22,588 for the nine months ended  September
30,  1999 to  $35,694  for the same  period  in 2000  primarily  due to a higher
allocation of the managing general partner's G&A being allocated  (limited to 3%
of oil and gas revenues) as a result of increased oil and gas revenues.

Depletion  was $77,504 for the nine months ended  September 30, 2000 compared to
$118,619  for the same period in 1999,  representing  a decrease of $41,115,  or
35%.  This  decrease  was due to an  increase in proved  reserves  due to higher
commodity  prices as compared to the same period in 1999 and a reduction  in the
Partnership's  net  depletable  basis  from  charges  taken in  accordance  with
Statement  of  Financial  Accounting  Standards  No.  121,  "Accounting  for the
Impairment  of Long- Lived Assets and for  Long-Lived  Assets to be Disposed Of"
("SFAS  121")  during the fourth  quarter of 1999,  offset by an increase in oil
production of 162 barrels for the nine months ended  September 30, 2000 compared
to the same period in 1999.


                                        8

<PAGE>



Three months ended September 30, 2000 compared with three months ended September
   30, 1999

Revenues:

The Partnership's  oil and gas revenues  increased 58% to $405,161 for the three
months ended  September  30, 2000 as compared to $255,759 for the same period in
1999. The increase in revenues  resulted from higher average prices received and
an increase in production.  For the three months ended September 30, 2000, 9,220
barrels of oil, 4,367 barrels of NGLs and 17,020 mcf of gas were sold, or 16,424
BOEs. For the three months ended September 30, 1999, 8,909 barrels of oil, 4,497
barrels of NGLs and 17,772 mcf of gas were sold, or 16,368 BOEs.

The average  price  received per barrel of oil  increased  $11.21,  or 58%, from
$19.33  during the three months ended  September 30, 1999 to $30.54 for the same
period in 2000. The average price  received per barrel of NGLs increased  $4.69,
or 42%, from $11.25  during the three months ended  September 30, 1999 to $15.94
for the same period in 2000. The average price received per mcf of gas increased
71% from $1.85 during the three months ended September 30, 1999 to $3.17 for the
same period in 2000.

Costs and Expenses:

Total costs and  expenses  increased  to  $174,737  for the three  months  ended
September  30,  2000 as compared  to  $153,429  for the same period in 1999,  an
increase of $21,308,  or 14%.  This  increase was due to increases in production
costs and G&A, offset by a decline in depletion.

Production costs were $135,775 for the three months ended September 30, 2000 and
$115,396 for the same period in 1999,  resulting in a $20,379 increase,  or 18%.
The increase was primarily due to higher production taxes of $12,830  associated
with higher oil and gas prices and additional well maintenance costs incurred to
stimulate well production of $2,666.

During this period, G&A increased, in aggregate,  35% from $10,343 for the three
months ended September 30, 1999 to $13,970 for the same period in 2000 primarily
due to a higher allocation of the managing general partner's G&A being allocated
(limited to 3% of oil and gas  revenues)  as a result of  increased  oil and gas
revenues.

Depletion was $24,992 for the three months ended  September 30, 2000 compared to
$27,690 for the same period in 1999,  representing a decrease of $2,698, or 10%.
This decrease was  attributable to an increase in proved reserves as a result of
higher  commodity  prices as compared to the same period in 1999 and a reduction
in the  Partnership's net depletable basis from charges taken in accordance with
SFAS 121  during  the  fourth  quarter  of 1999,  offset by an  increase  in oil
production of 311 barrels for the three months ended September 30, 2000 compared
to the same period in 1999.


                                     9

<PAGE>



Liquidity and Capital Resources

Net Cash Provided by Operating Activities

Net cash provided by operating  activities  increased  $436,302  during the nine
months ended  September 30, 2000 from the same period ended  September 30, 1999.
This increase was due to an increase in oil and gas sales  receipts of $505,118,
offset by  increases  of $56,727  in  production  costs paid and  $12,089 in G&A
expenses paid.

Net Cash Used in Investing Activities

The  Partnership's  investing  activities during the nine months ended September
30, 2000 and 1999 included expenditures related to equipment upgrades on various
oil and gas properties.

Proceeds from asset dispositions of $2,023 received during the nine months ended
September 30, 2000 were derived from the sale of equipment on one well.

Net Cash Used in Financing Activities

For the nine months ended September 30, 2000, cash distributions to the partners
were $597,062,  of which $5,971 was distributed to the managing  general partner
and $591,091 to the limited  partners.  For the same period ended  September 30,
1999,  cash  distributions  to the partners were  $136,608,  of which $1,366 was
distributed  to the  managing  general  partner  and  $135,242  to  the  limited
partners.

---------------

(1)    "Item 2. Management's  Discussion and Analysis of Financial Condition and
       Results of Operations"  contains forward looking  statements that involve
       risks and uncertainties. Accordingly, no assurances can be given that the
       actual  events and  results  will not be  materially  different  than the
       anticipated results described in the forward looking statements.


                           Part II. Other Information

Item 6.     Exhibits and Reports on Form 8-K

(a)    Exhibits

       27.1   Financial Data Schedule

(b)    Reports on Form 8-K - none


                                       10

<PAGE>


                        PARKER & PARSLEY 90-B CONV., L.P.
                        (A Delaware Limited Partnership)



                               S I G N A T U R E S



       Pursuant to the requirements of the Securities  Exchange Act of 1934, the
Registrant  has duly  caused  this  report  to be  signed  on its  behalf by the
undersigned thereunto duly authorized.


                                           PARKER & PARSLEY 90-B CONV., L.P.

                                  By:      Pioneer Natural Resources USA, Inc.,
                                             Managing General Partner




Dated:  November 9, 2000          By:      /s/ Rich Dealy
                                           -----------------------------------
                                           Rich Dealy, Vice President and
                                             Chief Accounting Officer



                                       11

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