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, 2001


                         Commission File No. 33-26097-10


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


                    Delaware                                   75-2347264
     -----------------------------------------           ---------------------
         (State or other jurisdiction of                    (I.R.S. Employer
          incorporation or organization)                 Identification Number)


5205 N. O'Connor Blvd., Suite 1400, 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-C CONV., L.P.

                                TABLE OF CONTENTS


                                                                      Page
                          Part I. Financial Information

Item 1.    Financial Statements

           Balance Sheets as of September 30, 2001 and
              December 31, 2000.....................................    3

           Statements of Operations for the three and nine
             months ended September 30, 2001 and 2000...............    4

           Statement of Partners' Capital for the nine months
             ended September 30, 2001...............................    5

           Statements of Cash Flows for the nine months ended
             September 30, 2001 and 2000............................    6

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

Item 2.    Management's Discussion and Analysis of Financial
             Condition and Results of Operations....................    8


                           Part II. Other Information

Item 6.    Exhibits and Reports on Form 8-K.........................   12

           Signatures...............................................   13


                                        2

<PAGE>



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

                          Part I. Financial Information

Item 1.     Financial Statements

                                 BALANCE SHEETS
<TABLE>

                                                   September 30,   December 31,
                                                       2001            2000
                                                   ------------    -----------
                                                   (Unaudited)
                 ASSETS

<S>                                                <C>             <C>
Current assets:
   Cash                                            $   219,883     $   106,593
   Accounts receivable - oil and gas sales              66,471         119,396
                                                    ----------      ----------
            Total current assets                       286,354         225,989
                                                    ----------      ----------
Oil and gas properties - at cost, based on the
   successful efforts accounting method              5,801,749       5,798,493
Accumulated depletion                               (5,051,593)     (5,000,618)
                                                    ----------      ----------
            Net oil and gas properties                 750,156         797,875
                                                    ----------      ----------
                                                   $ 1,036,510     $ 1,023,864
                                                    ==========      ==========
LIABILITIES AND PARTNERS' CAPITAL

Current liabilities:
   Accounts payable - affiliate                    $    34,540     $    14,074

Partners' capital:
   Managing general partner                              9,989          10,067
   Limited partners (7,531 interests)                  991,981         999,723
                                                    ----------      ----------
                                                     1,001,970       1,009,790
                                                    ----------      ----------
                                                   $ 1,036,510     $ 1,023,864
                                                    ==========      ==========
</TABLE>


The financial information included as of September 30, 2001 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-C CONV., L.P.
                        (A Delaware Limited Partnership)

                            STATEMENTS OF OPERATIONS
                                   (Unaudited)


<TABLE>

                                            Three months ended        Nine months ended
                                               September 30,            September 30,
                                         ----------------------    ----------------------
                                            2001        2000          2001         2000
                                         ---------    ---------    ---------    ---------
<S>                                      <C>          <C>          <C>          <C>
Revenues:
   Oil and gas                           $ 175,857    $ 256,283    $ 619,975    $ 671,181
   Interest                                  1,352        2,546        4,764        5,989
                                          --------     --------     --------     --------
                                           177,209      258,829      624,739      677,170
                                          --------     --------     --------     --------
Costs and expenses:
   Oil and gas production                   91,284       84,096      284,567      245,244
   General and administrative                5,380        8,742       20,059       21,832
   Impairment of oil and gas properties      8,163          -          8,163          -
   Depletion                                14,944       12,341       42,812       38,657
                                          --------     --------     --------     --------
                                           119,771      105,179      355,601      305,733
                                          --------     --------     --------     --------
Net income                               $  57,438    $ 153,650    $ 269,138    $ 371,437
                                          ========     ========     ========     ========
Allocation of net income:
   Managing general partner              $     575    $   1,536    $   2,692    $   3,714
                                          ========     ========     ========     ========
   Limited partners                      $  56,863    $ 152,114    $ 266,446    $ 367,723
                                          ========     ========     ========     ========
Net income per limited
   partnership interest                  $    7.55    $   20.20    $   35.38    $   48.83
                                          ========     ========     ========     ========
</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-C CONV., L.P.
                        (A Delaware Limited Partnership)

                         STATEMENT OF PARTNERS' CAPITAL
                                   (Unaudited)



<TABLE>

                                         Managing
                                         general      Limited
                                         partner      partners       Total
                                        ---------    ----------    ----------


<S>                                     <C>          <C>           <C>
Balance at January 1, 2001              $  10,067    $  999,723    $1,009,790

    Distributions                          (2,770)     (274,188)     (276,958)

    Net income                              2,692       266,446       269,138
                                         --------     ---------     ---------

Balance at September 30, 2001           $   9,989    $  991,981    $1,001,970
                                         ========     =========     =========

</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-C CONV., L.P.
                        (A Delaware Limited Partnership)

                            STATEMENTS OF CASH FLOWS
                                   (Unaudited)



<TABLE>

                                                         Nine months ended
                                                            September 30,
                                                      ------------------------
                                                         2001          2000
                                                      ----------    ----------
<S>                                                   <C>           <C>
Cash flows from operating activities:
   Net income                                         $  269,138    $  371,437
   Adjustments to reconcile net income to net
     cash provided by operating activities:
        Impairment of oil and gas properties               8,163           -
        Depletion                                         42,812        38,657
   Changes in assets and liabilities:
        Accounts receivable                               52,925       (31,185)
        Accounts payable                                  20,466        13,580
                                                       ---------     ---------
          Net cash provided by operating activities      393,504       392,489
                                                       ---------     ---------
Cash flows used in investing activities:
   Additions to oil and gas properties                    (3,256)      (15,801)

Cash flows used in financing activities:
   Cash distributions to partners                       (276,958)     (361,535)
                                                       ---------     ---------
Net increase in cash                                     113,290        15,153
Cash at beginning of period                              106,593       107,295
                                                       ---------     ---------
Cash at end of period                                 $  219,883    $  122,448
                                                       =========     =========

</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-C CONV., L.P.
                        (A Delaware Limited Partnership)

                          NOTES TO FINANCIAL STATEMENTS
                               September 30, 2001
                                   (Unaudited)

Note 1.     Organization and nature of operations

Parker & Parsley 90-C 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, 2001 and for the three and nine months  ended
September 30, 2001 and 2000 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, 2000 financial  statements to conform to
the September 30, 2001 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 rules 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, 2000, 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,  Suite 1400, Irving,
Texas 75039-3746.

Note 3.     Impairment of long-lived assets

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"),  the  Partnership  reviews its proved oil and gas
properties for impairment  whenever events and circumstances  indicate a decline
in the  recoverability  of the carrying value of the  Partnership's  oil and gas
properties.  The Partnership has estimated the expected future cash flows of its
oil and gas properties as of September 30, 2001, based on proved  reserves,  and
compared such estimated  future cash flows to the respective  carrying amount of
the oil and gas  properties to determine if the carrying  amounts were likely to
be  recoverable.  For those proved oil and gas properties for which the carrying
amount exceeded the estimated future cash flows, an impairment was determined to
exist; therefore,  the Partnership adjusted the carrying amount of those oil and
gas properties to their  fair value as determined  by discounting their expected

                                        7

<PAGE>



future cash flows at a discount rate commensurate with the risks involved in the
industry.  As  a  result,  the  Partnership  recognized  a  non-cash  impairment
provision of $8,163 related to its proved oil and gas properties during the nine
months ended September 30, 2001.

Note 4.     Proposal to acquire Partnership

On October 22,  2001,  Pioneer  Natural  Resources  Company  ("Pioneer")  mailed
materials to the limited  partners of the Partnership  soliciting their approval
of an agreement and plan of merger among Pioneer, Pioneer Natural Resources USA,
Inc. ("Pioneer USA"), a wholly-owned subsidiary of Pioneer, and the Partnership.
Pioneer has valued the Partnership interest at $1,884,667 of which $1,858,388 is
attributable to the limited partners, excluding Pioneer USA in its capacity as a
general  partner or a limited  partner.  If a majority of the  limited  partners
approve the transaction,  each limited partner will receive their  proportionate
share of the value in the form of Pioneer common stock.

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

Results of Operations

Nine months ended September 30, 2001 compared with nine months ended September
   30, 2000

Revenues:

The  Partnership's  oil and gas  revenues  decreased 8% to $619,975 for the nine
months ended  September  30, 2001 as compared to $671,181 for the same period in
2000. The decrease in revenues  resulted from a decrease in production and lower
average  prices  received  for oil and natural gas liquids  ("NGLs"),  offset by
higher average prices  received for gas. For the nine months ended September 30,
2001,  16,610  barrels of oil,  4,687 barrels of NGLs and 25,888 mcf of gas were
sold, or 25,612 barrel of oil  equivalents  ("BOEs").  For the nine months ended
September 30, 2000,  17,723 barrels of oil, 7,280 barrels of NGLs and 25,305 mcf
of gas were sold,  or 29,221  BOEs.  Due to the decline  characteristics  of the
Partnership's  oil and gas  properties,  management  expects a certain amount of
decline  in  production  in the  future  until  the  Partnership's  economically
recoverable reserves are fully depleted.

The average price received per barrel of oil decreased $1.23, or 4%, from $28.39
for the nine months  ended  September  30, 2000 to $27.16 for the same period in
2001. The average price received per barrel of NGLs decreased  $.31, or 2%, from
$14.08  during the nine months ended  September  30, 2000 to $13.77 for the same
period in 2001.  The average  price  received per mcf of gas  increased 55% from
$2.59  during the nine  months  ended  September  30, 2000 to $4.02 for the same
period in 2001. 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, 2001.

                                        8

<PAGE>



Costs and Expenses:

Total  costs and  expenses  increased  to  $355,601  for the nine  months  ended
September  30,  2001 as compared  to  $305,733  for the same period in 2000,  an
increase of $49,868,  or 16%.  This  increase was due to increases in production
costs,  the  impairment of oil and gas  properties  and  depletion,  offset by a
decline in general and administrative expenses ("G&A").

Production  costs were $284,567 for the nine months ended September 30, 2001 and
$245,244 for the same period in 2000,  resulting  in an increase of $39,323,  or
16%. The increase was primarily due to additional well  maintenance and workover
costs incurred to stimulate production and higher ad valorem taxes.

G&A's  components are independent  accounting and engineering  fees and managing
general partner personnel and operating costs. During this period, G&A decreased
8% from $21,832 for the nine months ended  September 30, 2000 to $20,059 for the
same period in 2001, primarily due to a lower percentage of the managing general
partner's  G&A being  allocated  (limited  to 3% of oil and gas  revenues)  as a
result of decreased oil and gas revenues.

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"),  the  Partnership  reviews its proved oil and gas
properties for impairment  whenever events and circumstances  indicate a decline
in the  recoverability  of the carrying value of the  Partnership's  oil and gas
properties.  The Partnership has estimated the expected future cash flows of its
oil and gas properties as of September 30, 2001, based on proved  reserves,  and
compared such estimated  future cash flows to the respective  carrying amount of
the oil and gas  properties to determine if the carrying  amounts were likely to
be  recoverable.  For those proved oil and gas properties for which the carrying
amount exceeded the estimated future cash flows, an impairment was determined to
exist; therefore,  the Partnership adjusted the carrying amount of those oil and
gas properties to their fair value as determined by  discounting  their expected
future cash flows at a discount rate commensurate with the risks involved in the
industry.  As  a  result,  the  Partnership  recognized  a  non-cash  impairment
provision of $8,163 related to its proved oil and gas properties during the nine
months ended September 30, 2001.

Depletion  was $42,812 for the nine months ended  September 30, 2001 as compared
to $38,657 for the same period in 2000,  representing an increase of $4,155,  or
11%. This increase was the result of a reduction in proved  reserves  during the
period  ended  September  30, 2001 due to lower  commodity  prices,  offset by a
decrease in oil production of 1,113 barrels for the nine months ended  September
30, 2001 as compared to the same period in 2000.

Three months ended September 30, 2001 compared with three months ended September
   30, 2000

Revenues:

The Partnership's  oil and gas revenues  decreased 31% to $175,857 for the three
months ended  September  30, 2001 as compared to $256,283 for the same period in
2000.  The decrease in revenues  resulted from a decline in production and lower
average prices  received.  For the three months ended September 30, 2001,  5,105
barrels of oil,  2,210 barrels of NGLs and 8,083 mcf of gas were sold,  or 8,662

                                        9

<PAGE>



BOEs. For the three months ended September 30, 2000, 5,764 barrels of oil, 2,853
barrels  of NGLs and 11,213 mcf of gas were  sold,  or 10,486  BOEs.  Due to the
decline characteristics of the Partnership's oil and gas properties,  management
expects a certain  amount of  decline  in  production  in the  future  until the
Partnership's economically recoverable reserves are fully depleted.

The average  price  received per barrel of oil  decreased  $4.00,  or 13%,  from
$30.30 for the three  months  ended  September  30,  2000 to $26.30 for the same
period in 2001. The average price  received per barrel of NGLs decreased  $4.84,
or 30%, from $16.07  during the three months ended  September 30, 2000 to $11.23
for the same period in 2001. The average price received per mcf of gas decreased
35% from $3.19 during the three months ended September 30, 2000 to $2.07 for the
same period in 2001.

Costs and Expenses:

Total costs and  expenses  increased  to  $119,771  for the three  months  ended
September  30,  2001 as compared  to  $105,179  for the same period in 2000,  an
increase  of  $14,592,  or  14%.  This  increase  was  due to  increases  in the
impairment of oil and gas properties,  production costs and depletion, offset by
a decline in G&A.

Production  costs were $91,284 for the three months ended September 30, 2001 and
$84,096 for the same period in 2000, resulting in a $7,188 increase,  or 9%. The
increase  was  primarily  due to higher ad  valorem  taxes and  additional  well
maintenance  costs  incurred  to  stimulate  well  production,  offset  by lower
production taxes.

During this  period,  G&A  decreased  38% from $8,742 for the three months ended
September  30,  2000 to $5,380 for the same period in 2001,  primarily  due to a
lower percentage of the managing general partner's G&A being allocated  (limited
to 3% of oil and gas revenues) as a result of decreased oil and gas revenues.

The Partnership  recognized a non-cash impairment provision of $8,163 related to
its proved oil and gas  properties  during the three months ended  September 30,
2001.

Depletion was $14,944 for the three months ended  September 30, 2001 as compared
to $12,341 for the same period in 2000,  representing an increase of $2,603,  or
21%. This increase was the result of a reduction in proved  reserves  during the
period ended September 30, 2001 as a result of lower commodity prices, offset by
a decline in oil production of 659 barrels for the three months ended  September
30, 2001 as compared to the same period in 2000.

Liquidity and Capital Resources

Net Cash Provided by Operating Activities

Net cash  provided by  operating  activities  increased  $1,015  during the nine
months ended  September 30, 2001 from the same period ended  September 30, 2000.
This  increase  was due to a  reduction  in working  capital  of  $90,996  and a
decrease of $1,773 in G&A expenses, offset by an increase in production costs of
$39,323 and a decrease in oil and gas sales receipts of $52,431. The decrease in
oil and gas receipts  resulted from the decline in production of $63,623  during
2001 as compared to the same period in 2000 and a decrease in the average prices
received for oil and  NGLs of $25,167,  offset by an increase  in average prices

                                       10

<PAGE>



received for gas of $36,359.  The increase in production costs was primarily due
to additional  well  maintenance  and workover  costs incurred to stimulate well
production and higher ad valorem taxes. The decrease in G&A was primarily due to
a lower  percentage  of the  managing  general  partner's  G&A  being  allocated
(limited to 3% of oil and gas  revenues)  as a result of  decreased  oil and gas
revenues.

Net Cash Used in Investing Activities

The  Partnership's  investing  activities during the nine months ended September
30, 2001 and 2000 were for expenditures related to equipment upgrades on various
oil and gas properties.

Net Cash Used in Financing Activities

For the nine months ended September 30, 2001, cash distributions to the partners
were $276,958,  of which $2,770 was distributed to the managing  general partner
and $274,188 to the limited  partners.  For the same period ended  September 30,
2000,  cash  distributions  to the partners were  $361,535,  of which $3,615 was
distributed  to the  managing  general  partner  and  $357,920  to  the  limited
partners.

During  2001,  the  Partnership  made  distributions  in  March  and July but no
distributions  were made by the Partnership during September pending the vote of
the proposed merger of the Partnership into Pioneer Natural  Resources USA, Inc.
("Pioneer USA"). For further information, see "Proposal to acquire partnerships"
below.

Proposal to acquire partnerships

On October 22,  2001,  Pioneer  Natural  Resources  Company  ("Pioneer")  mailed
definitive materials (the "proxy  statement/prospectus") to solicit the approval
of limited partners of 46 Parker & Parsley limited  partnerships,  including the
Partnership,  of an agreement and plan of merger among  Pioneer,  Pioneer USA, a
wholly-owned subsidiary of Pioneer, and those limited partnerships.  The special
meetings of the limited partners to consider and vote on the merger proposal are
scheduled  for  December  20,  2001.  The record  date to  identify  the limited
partners who are  entitled to notice of and to vote at the special  meetings was
September  21, 2001.  Each  partnership  that approves the agreement and plan of
merger and the other related  merger  proposals will merge with and into Pioneer
USA.  As a result,  the  partnership  interests  of those  partnerships  will be
converted into the right to receive Pioneer common stock.

The proxy  statement/prospectus  is  non-binding  and is subject to, among other
things,  consideration  of offers from third parties to purchase any partnership
or its assets and the majority approval of the limited partnership  interests in
each partnership.

A copy of the proxy  statement/prospectus  may be obtained  without  charge upon
request from Pioneer Natural Resources Company, 5205 North O'Connor Blvd., Suite
1400, Irving, Texas 75039, Attention: Investor Relations.

The limited partners are urged to read the proxy statement/prospectus of Pioneer
filed with the Securities and Exchange  Commission because it contains important
information about the proposed mergers,  including  information about the direct
and indirect  interests of Pioneer USA and  Pioneer in the mergers.  The limited

                                       11

<PAGE>



partners may also obtain the final proxy statement/prospectus and other relevant
documents  relating to the  proposed  mergers free through the internet web site
that the Securities and Exchange Commission maintains at www.sec.gov.

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

(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

(b)   Reports on Form 8-K - none



                                       12

<PAGE>


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

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




Dated:  November 7, 2001           By:    /s/ Rich Dealy
                                           ---------------------------------
                                           Rich Dealy, Vice President and
                                             Chief Accounting Officer



                                       13

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