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


                                    FORM 10-Q


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

                  For the quarterly period ended June 30, 1998

                                       or

      /   /     Transition Report Pursuant to Section 13 or 15(d)
                     of the Securities Exchange Act of 1934
                For the transition period from _______ to _______


                         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)


303 West Wall, Suite 101, Midland, Texas                    79701
(Address of principal executive offices)                  (Zip code)


       Registrant's Telephone Number, including area code : (915) 683-4768

                                 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 June 30, 1998 and
              December 31, 1997  ......................................    3

           Statements of Operations for the three and six
             months ended June 30, 1998 and 1997.......................    4

           Statement of Partners' Capital for the six months
             ended June 30, 1998.......................................    5

           Statements of Cash Flows for the six months ended
             June 30, 1998 and 1997....................................    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............................   11

           27.1   Financial Data Schedule

           Signatures..................................................   12






                                        2

<PAGE>



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

                          Part I. Financial Information

Item 1.   Financial Statements

                                 BALANCE SHEETS
                                                     June 30,     December 31,
                                                       1998           1997
                                                   -----------    -----------
                                                   (Unaudited)
                 ASSETS

Current assets:
  Cash and cash equivalents, including interest
     bearing deposits of $75,379 at June 30
     and $87,310 at December 31                    $    75,493    $    87,423
  Accounts receivable - oil and gas sales               45,852         69,891
                                                    ----------     ----------
         Total current assets                          121,345        157,314
                                                    ----------     ----------
Oil and gas properties - at cost, based on the
  successful efforts accounting method               5,758,789      5,751,870
Accumulated depletion                               (4,552,179)    (4,497,380)
                                                    ----------     ----------
         Net oil and gas properties                  1,206,610      1,254,490
                                                    ----------     ----------
                                                   $ 1,327,955    $ 1,411,804
                                                    ==========     ==========
LIABILITIES AND PARTNERS' CAPITAL

Current liabilities:
  Accounts payable - affiliate                     $    26,268    $    23,946

Partners' capital:
  Managing general partner                              12,986         13,848
  Limited partners (7,531 interests)                 1,288,701      1,374,010
                                                    ----------     ----------
                                                     1,301,687      1,387,858
                                                    ----------     ----------
                                                   $ 1,327,955    $ 1,411,804
                                                    ==========     ==========



   The financial information included as of June 30, 1998 has been prepared by
           management 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)




                                    Three months ended       Six months ended
                                         June 30,                June 30,
                                  ---------------------   ---------------------
                                     1998        1997        1998        1997
                                  ---------   ---------   ---------   ---------
Revenues:
   Oil and gas                    $ 108,532   $ 156,746   $ 228,491   $ 344,771
   Interest                           1,150       1,559       2,434       2,939
   Gain on disposition of assets        -           793         -           793
                                   --------    --------    --------    --------
                                    109,682     159,098     230,925     348,503
                                   --------    --------    --------    --------
Costs and expenses:
   Oil and gas production            88,012      77,988     168,981     166,051
   General and administrative         3,608       4,858       7,593      11,018
   Depletion                         26,902      26,789      54,799      52,230
                                   --------    --------    --------    --------
                                    118,522     109,635     231,373     229,299
                                   --------    --------    --------    --------
Net income (loss)                 $  (8,840)  $  49,463   $    (448)  $ 119,204
                                   ========    ========    ========    ========
Allocation of net income (loss):
   Managing general partner       $     (88)  $     495   $      (4)  $   1,192
                                   ========    ========    ========    ========
   Limited partners               $  (8,752)  $  48,968   $    (444)  $ 118,012
                                   ========    ========    ========    ========
Net income (loss) per limited
   partnership interest           $   (1.16)  $    6.50   $    (.06)  $   15.67
                                   ========    ========    ========    ========
Distributions per limited
   partnership interest           $    3.59   $   12.04   $   11.27   $   27.89
                                   ========    ========    ========    ========


         The financial information included herein has been prepared by
           management 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)





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


Balance at January 1, 1998           $  13,848     $1,374,010     $1,387,858

    Distributions                         (858)       (84,865)       (85,723)

    Net loss                                (4)          (444)          (448)
                                      --------      ---------      ---------

Balance at June 30, 1998             $  12,986     $1,288,701     $1,301,687
                                      ========      =========      =========





         The financial information included herein has been prepared by
           management 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)


                                                           Six months ended
                                                               June 30,
                                                       ------------------------
                                                          1998          1997
                                                       ----------    ----------
Cash flows from operating activities:
   Net income (loss)                                   $     (448)   $  119,204
   Adjustments to reconcile net income (loss) to
     net cash provided by operating activities:
        Depletion                                          54,799        52,230
        Gain on disposition of assets                         -            (793)
   Changes in assets and liabilities:
        Accounts receivable                                24,039        60,293
        Accounts payable                                    2,322         4,184
                                                        ---------     ---------
           Net cash provided by operating activities       80,712       235,118
                                                        ---------     ---------
Cash flows from investing activities:
   Additions to oil and gas properties                     (6,919)       (4,787)
   Proceeds from asset dispositions                           -             793
                                                        ---------     ---------
           Net cash used in operating activities           (6,919)       (3,994)
                                                        ---------     ----------
Cash flows from financing activities:
   Cash distributions to partners                         (85,723)     (212,145)
                                                        ---------     ----------
Net increase (decrease) in cash and cash equivalents      (11,930)       18,979
Cash and cash equivalents at beginning of period           87,423        79,564
                                                        ---------     ---------
Cash and cash equivalents at end of period             $   75,493    $   98,543
                                                        =========     =========



         The financial information included herein has been prepared by
           management 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
                                  June 30, 1998
                                   (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  primarily 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 June 30, 1998 and for the three and six months ended June 30,
1998 and 1997 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  information  and  footnote  disclosure  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, 1997, 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

Six months ended June 30, 1998 compared with six months ended
   June 30, 1997

Revenues:

The Partnership's  oil and gas revenues  decreased 34% to $228,491 from $344,771
for the six months ended June 30, 1998 and 1997,  respectively.  The decrease in
revenues  resulted from lower average prices received,  offset by an increase in
production. For the six months ended June 30, 1998, 12,574 barrels of oil, 3,737
barrels  of natural  gas liquids  ("NGLs") and  14,569 mcf of gas were sold,  or

                                        7

<PAGE>



18,739  barrel of oil  equivalents  ("BOEs").  For the six months ended June 30,
1997, 13,014 barrels of oil and 29,803 mcf of gas were sold, or 17,981 BOEs.

As of September 30, 1997, the Partnership began accounting for processed natural
gas   production  as  processed   natural  gas  liquids  and  dry  residue  gas.
Consequently,  separate  product volumes will not be comparable to periods prior
to September 30, 1997.  Also,  prices for gas products will not be comparable as
the price per mcf for  natural  gas for the three and six months  ended June 30,
1998 is the price received for dry residue gas and the price per mcf for natural
gas for the  three and six  months  ended  June 30,  1997 is a price for wet gas
(i.e., natural gas liquids combined with dry residue gas).

The average  price  received per barrel of oil  decreased  $6.32,  or 31%,  from
$20.46 for the six months  ended June 30,  1997 to $14.14 for the same period in
1998.  The average price received per barrel of NGLs during the six months ended
June 30, 1998 was $7.51. The average price received per mcf of gas decreased 41%
from  $2.63  during the six months  ended  June 30,  1997 to $1.56 in 1998.  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 six months ended
June 30, 1998.

During  most of 1997,  the  Partnership  benefitted  from  higher  oil prices as
compared to previous  years.  However,  during the fourth  quarter of 1997,  oil
prices began a downward  trend that has  continued  into 1998. On July 29, 1998,
the market  price for West Texas  intermediate  crude was $11.58 per  barrel.  A
continuation of the oil price environment  experienced  during the first half of
1998 will have an adverse  effect on the  Partnership's  revenues and  operating
cash flow and could result in additional  decreases in the carrying value of the
Partnership's oil and gas properties.

A gain on  disposition of assets of $793,  received  during the six months ended
June 30, 1997, was attributable to credits received from the disposal of oil and
gas equipment on one fully depleted well.

Costs and Expenses:

Total costs and expenses increased to $231,373 for the six months ended June 30,
1998 as compared to $229,299 for the same period in 1997, an increase of $2,074.
This increase was due to increases in production costs and depletion,  offset by
a decrease in general and administrative expenses, ("G&A").

Production  costs  were  $168,981  for the six months  ended  June 30,  1998 and
$166,051  for the same  period  in 1997,  resulting  in a $2,930  increase.  The
increase was due to additional well  maintenance  costs incurred in an effort to
stimulate well production, offset by a decline in production 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, in aggregate, 31% from $11,018 for the six months ended June 30, 1997
to $7,593 for the same period in 1998.

                                        8

<PAGE>



Depletion was $54,799 for the six months ended June 30, 1998 compared to $52,230
for the same  period in 1997.  This  represented  an increase  in  depletion  of
$2,569,  or 5%. This  increase was primarily  attributable  to a decrease in oil
reserves  during  the six  months  ended  June  30,  1998 as a  result  of lower
commodity prices, offset by a reduction in oil production of 440 barrels for the
period ended June 30, 1998 compared to the same period in 1997.

Three months ended June 30, 1998 compared with three months ended
   June 30, 1997

Revenues:

The Partnership's  oil and gas revenues  decreased 31% to $108,532 from $156,746
for the three months ended June 30, 1998 and 1997, respectively. The decrease in
revenues  resulted from lower average prices received,  offset by an increase in
production.  For the three  months ended June 30,  1998,  6,135  barrels of oil,
1,914  barrels of NGLs and 6,742 mcf of gas were sold,  or 9,173  BOEs.  For the
three  months ended June 30,  1997,  6,418  barrels of oil and 15,197 mcf of gas
were sold, or 8,951 BOEs.

The average  price  received per barrel of oil  decreased  $5.46,  or 29%,  from
$18.90 for the three months ended June 30, 1997 to $13.44 for the same period in
1998.  The average  price  received  per barrel of NGLs during the three  months
ended  June 30,  1998 was  $7.96.  The  average  price  received  per mcf of gas
decreased 31% from $2.33 during the three months ended June 30, 1997 to $1.61 in
1998.

A gain on disposition of assets of $793,  received during the three months ended
June 30, 1997, was attributable to credits received from the disposal of oil and
gas equipment on one fully depleted well.

Costs and Expenses:

Total costs and  expenses  increased to $118,522 for the three months ended June
30, 1998 as compared  to  $109,635  for the same period in 1997,  an increase of
$8,887,  or 8%. This  increase  was due to  increases  in  production  costs and
depletion, offset by a decrease in G&A.

Production  costs were  $88,012  for the three  months  ended June 30,  1998 and
$77,988 for the same period in 1997,  resulting in a $10,024  increase,  or 13%.
The increase was due to additional well maintenance  costs incurred in an effort
to stimulate well production, offset by a decline in production 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,  in  aggregate,  26% from $4,858 for the three  months ended June 30,
1997 to $3,608 for the same period in 1998.

Depletion  was $26,902  for the three  months  ended June 30,  1998  compared to
$26,789 for the same period in 1997.  This  represented an increase in depletion

                                        9

<PAGE>



of $113. This increase was primarily  attributable to a decrease in oil reserves
during  the three  months  ended  June 30,  1998 as a result of lower  commodity
prices,  offset by a reduction  in oil  production  of 283 barrels for the three
months ended June 30, 1998 compared to the same period in 1997.

Liquidity and Capital Resources

Net Cash Provided by Operating Activities

Net cash  provided by operating  activities  decreased  $154,406  during the six
months  ended  June 30,  1998 from the same  period  ended June 30,  1997.  This
decrease  was due to a decline in oil and gas sales  receipts and an increase in
production costs paid, offset by a decline in G&A expenses paid.

Net Cash Used in Investing Activities

The  Partnership's  principal  investing  activities during the six months ended
June 30, 1998 and 1997 were for expenditures related to equipment replacement on
various oil and gas properties.

Proceeds from asset  dispositions  of $793 were  received  during the six months
ended June 30, 1997 from the salvage of equipment on one fully depleted well.

Net Cash Used in Financing Activities

Cash  was   sufficient  for  the  six  months  ended  June  30,  1998  to  cover
distributions  to the partners of $85,723 of which $858 was  distributed  to the
managing  general  partner  and $84,865 to the  limited  partners.  For the same
period  ended  June 30,  1997,  cash was  sufficient  for  distributions  to the
partners of $212,145 of which $2,121 was  distributed  to the  managing  general
partner and $210,024 to the limited partners.

It is expected  that future net cash  provided by operating  activities  will be
sufficient for any capital expenditures and any distributions. As the production
from the properties declines, distributions are also expected to decrease.

Information systems for the year 2000

The managing general partner will be required to modify its information  systems
in order to  accurately  process  Partnership  data  referencing  the year 2000.
Because of the importance of occurrence  dates in the oil and gas industry,  the
consequences of not pursuing these  modifications  could be very  significant to
the Partnership's ability to manage and report operating activities.  Currently,
the managing general partner plans to contract with third parties to perform the
software  programming  changes  necessary to correct any existing  deficiencies.
Such  programming  changes are  anticipated  to be completed  and tested by June

                                       10

<PAGE>



1999. The managing  general  partner will allocate a portion of the costs of the
year 2000 programming  charges to the Partnership when they are incurred,  along
with recurring general and administrative  expenses.  Although the costs are not
estimable at this time, they should not be significant to the Partnership.

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

(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)     Form 8-K - none


                                       11

<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:  August 5, 1998              By:    /s/ Rich Dealy
                                           ----------------------------------
                                           Rich Dealy, Vice President and
                                           Chief Accounting Officer




                                       12

<PAGE>