SECURITIES AND EXCHANGE COMMISSION
                                       
                            WASHINGTON, D.C.  20549

                                   FORM 10-Q
                                       

(Mark One)
  /X/           QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d)
                    OF THE SECURITIES EXCHANGE ACT OF 1934
               For The Quarterly Period Ended September 28, 1997
                                       
                                      OR
                                       
  / /          TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d)
                    OF THE SECURITIES EXCHANGE ACT OF 1934
                                       
                       Commission File Number 333-17827
                                       
                               ISP HOLDINGS INC.
            (Exact name of registrant as specified in its charter)


        Delaware                                               51-0376469
(State of Incorporation)                                  (I. R. S. Employer
                                                           Identification No.)

 818 Washington Street, Wilmington, Delaware                     19801
(Address of principal executive offices)                       (Zip Code)

Registrant's telephone number, including area code           (302) 428-0847

                               (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  / /


As of November 11, 1997, 1,759,154 shares of the Registrant's common stock (par
value, $.01 per share) were outstanding.
<PAGE>

                        Part I - FINANCIAL INFORMATION
                         Item 1 - FINANCIAL STATEMENTS
                                       
                               ISP HOLDINGS INC.
                                       
                       CONSOLIDATED STATEMENTS OF INCOME
                     (Thousands, except per share amounts)


                                          Third Quarter Ended   Nine Months
Ended
                                          -------------------- ----------------
---
                                          Sept. 29, Sept. 28,  Sept. 29, Sept.
28,
                                             1996      1997       1996
1997
                                          --------- ---------  --------- ------
---

Net sales................................ $173,569  $183,600   $544,135
$572,606
                                          --------  --------   --------  ------
--

Costs and expenses:
  Cost of products sold..................  100,277   105,861    320,295
336,380
  Selling, general and administrative....   36,501    39,782    108,236
116,274
  Goodwill amortization..................    3,300     3,345      9,900
9,980
                                          --------  --------   --------  ------
--
    Total costs and expenses.............  140,078   148,988    438,431
462,634
                                          --------  --------   --------  ------
--

Operating income.........................   33,491    34,612    105,704
109,972
Interest expense.........................   (6,961)  (17,975)   (21,879)
(55,505)
Equity in earnings of joint venture......    1,798     1,517      4,948
4,263
Other income, net........................    2,984    10,414      9,429
23,803
                                          --------  --------   --------  ------
--
Income from continuing operations before
  income taxes and extraordinary item....   31,312    28,568     98,202
82,533
Income taxes.............................  (11,199)  (10,548)   (35,647)
(30,128)
Minority interest in income of
  subsidiary.............................   (3,392)   (3,594)   (10,802)
(11,293)
                                          --------  --------   --------  ------
--
Income from continuing operations before
  extraordinary item.....................   16,721    14,426     51,753
41,112
                                          --------  --------   --------  ------
--
Discontinued operations:
  Loss from discontinued operations, net
    of income tax benefits...............   (6,277)        -    (17,422)
-
  Gain on sale of discontinued operation,
    net of income taxes of $30,648.......   43,637         -     43,637
-
                                          --------  --------   --------  ------
--
Income from discontinued operations......   37,360         -     26,215
-
                                          --------  --------   --------  ------
--
Income before extraordinary item.........   54,081    14,426     77,968
41,112
Extraordinary item, net of income tax
  benefit of $5,016......................        -         -     (8,186)
-
                                          --------  --------   --------  ------
--
Net income............................... $ 54,081  $ 14,426   $ 69,782  $
41,112
                                          ========  ========   ========
========
                                       
                                       
                                       
                                       
                                       
                                       
                See Notes to Consolidated Financial Statements



                                       
                                       
                                       
                                       1
<PAGE>
                               ISP HOLDINGS INC.
                                       
                          CONSOLIDATED BALANCE SHEETS


                                                    December 31,  Sept. 28,
                                                        1996         1997
                                                    ------------  ----------
ASSETS                                                     (Thousands)
Current Assets:
  Cash and cash equivalents.......................   $   17,938   $   29,783
  Investments in trading securities...............        2,334       46,614
  Investments in available-for-sale securities....      158,698      122,438
  Investments in held-to-maturity securities......        1,977          525
  Other short-term investments....................       21,435       22,100
  Accounts receivable, trade, net.................       66,875       76,346
  Accounts receivable, other......................       12,835       22,890
  Receivable from affiliates, net.................        5,236        7,923
  Inventories.....................................      108,586      113,025
  Net current assets of discontinued operations...      206,708            -
  Other current assets............................       13,239       17,431
                                                     ----------   ----------
    Total Current Assets..........................      615,861      459,075
Property, plant and equipment, net................      493,243      508,201
Goodwill, net.....................................      421,017      413,199
Other assets......................................       70,311       65,800
                                                     ----------   ----------
Total Assets......................................   $1,600,432   $1,446,275
                                                     ==========   ==========

LIABILITIES AND SHAREHOLDER'S EQUITY
Current Liabilities:
  Short-term debt.................................   $   22,282   $   16,596
  Current maturities of long-term debt............          610          423
  Accounts payable................................       43,465       57,939
  Accrued liabilities.............................       66,907       75,891
  Income taxes....................................        5,751        5,330
                                                     ----------   ----------
    Total Current Liabilities.....................      139,015      156,179
                                                     ----------   ----------
Long-term debt less current maturities............      834,284      812,715
                                                     ----------   ----------
Deferred income taxes.............................       53,612       58,620
                                                     ----------   ----------
Net noncurrent liabilities of discontinued
  operations......................................      353,880            -
                                                     ----------   ----------
Other liabilities.................................       60,758       55,687
                                                     ----------   ----------
Minority interest in subsidiary...................      116,230      121,121
                                                     ----------   ----------

Shareholder's Equity:
  Cumulative redeemable convertible preferred
    stock, $.01 par value per share; 800,000
    shares authorized:  0 shares issued...........            -            -
  Common stock, $.01 par value per share;
    3,000,000 shares authorized: 1,769,054
    shares issued.................................            -           18
  Additional paid-in capital......................       46,426      213,573
  Treasury stock, at cost - 9,900 shares..........            -         (839)
  Retained earnings (accumulated deficit).........      (13,925)      27,187
  Cumulative translation adjustment and other.....       10,152        2,014
                                                     ----------   ----------
    Shareholder's Equity..........................       42,653      241,953
                                                     ----------   ----------
Total Liabilities and Shareholder's Equity .......   $1,600,432   $1,446,275
                                                     ==========   ==========


                                       
                See Notes to Consolidated Financial Statements
                                       
                                       
                                       2
<PAGE>
                               ISP HOLDINGS INC.
                                       
                     CONSOLIDATED STATEMENTS OF CASH FLOWS


                                                           Nine Months Ended
                                                          --------------------
                                                          Sept. 29,  Sept. 28,
                                                             1996       1997
                                                          ---------  ---------
                                                               (Thousands)

Cash and cash equivalents, beginning of period..........  $ 14,080   $ 17,938
                                                          --------   --------

Cash provided by operating activities:
  Net income............................................    69,782     41,112
  Adjustments to reconcile net income to net
    cash provided by operating activities:
      Income from discontinued operations...............   (26,215)         -
      Extraordinary item................................     8,186          -
      Depreciation......................................    28,183     30,936
      Goodwill amortization.............................     9,900      9,980
      Deferred income taxes.............................   (11,340)    23,521
  (Increase) decrease in working capital items..........    (3,015)    (6,713)
  Purchases of trading securities.......................   (34,228)  (132,330)
  Proceeds from sales of trading securities.............    39,841     96,278
  Increase in net receivable from related parties.......    (5,016)    (2,687)
  Change in cumulative translation adjustment...........    (4,005)    (7,343)
  Change in minority interest in subsidiary.............    10,015     10,113
  Other, net............................................       399      5,530
                                                          --------   --------
    Net cash provided by operating activities...........    82,487     68,397
                                                          --------   --------

Cash provided by (used in) investing activities:
  Capital expenditures and acquisition..................   (35,669)   (45,834)
  Proceeds from sale of discontinued operation..........    89,464          -
  Other - discontinued operations.......................   (83,027)         -
  Purchases of available-for-sale securities............  (194,126)  (213,708)
  Purchases of held-to-maturity securities..............    (9,534)    (1,623)
  Proceeds from sales of available-for-sale securities..   227,838    239,317
  Proceeds from held-to-maturity securities.............    10,033      3,075
                                                          --------   --------
    Net cash provided by (used in) investing activities.     4,979    (18,773)
                                                          --------   --------

Cash provided by (used in) financing activities:
  Decrease in short-term debt...........................   (14,013)    (5,686)
  Decrease in borrowings under revolving
    credit facility.....................................   (40,800)   (21,425)
  Other increase (decrease) in long-term debt, net......       185       (429)
  Decrease in loans from affiliate......................   (19,060)         -
  Financing fees........................................      (146)      (749)
  Repurchases of common stock...........................         -       (839)
  Subsidiary's repurchases of common stock..............   (10,365)   (10,240)
  Dividends and distributions to parent company.........   (67,996)         -
  Capital contribution from parent company..............    61,558          -
  Other.................................................       858      1,589
                                                          --------   --------
    Net cash used in financing activities...............   (89,779)   (37,779)
                                                          --------   --------
Net change in cash and cash equivalents.................    (2,313)    11,845
                                                          --------   --------
Cash and cash equivalents, end of period................  $ 11,767   $ 29,783
                                                          ========   ========

Supplemental Cash Flow Information:
  Cash paid during the period for:
    Interest (net of amount capitalized)................  $ 28,175   $ 54,276
    Income taxes........................................     5,825      3,261


                See Notes to Consolidated Financial Statements
                                       
                                       
                                       3
<PAGE>
                  NOTES TO CONSOLIDATED FINANCIAL STATEMENTS


     The "Company" refers to ISP Holdings Inc. and its subsidiaries, and the
"Registrant" refers to ISP Holdings Inc.  These consolidated financial
statements have been prepared on a basis which retroactively reflects the
formation of the Registrant, as discussed in Note A below, for all periods
presented and reflect, in the opinion of the Registrant, all adjustments
necessary to present fairly the financial position of the Company at
December 31, 1996 and September 28, 1997, and the results of operations and
cash flows for the periods ended September 29, 1996 and September 28, 1997.
All adjustments are of a normal recurring nature.  These financial statements
should be read in conjunction with the annual financial statements and notes
thereto included in Amendment No. 2 to the Registrant's Form S-4 Registration
Statement (Registration No. 333-17827) (the "Form S-4").


NOTE A:        Prior to January 1, 1997, the Registrant was a wholly owned
          subsidiary of GAF Corporation ("GAF").  The Registrant was formed on
          August 6, 1996, and 10 shares of its common stock were issued to GAF
          in exchange for all of the capital stock of G-I Holdings Inc. ("G-I
          Holdings").  On January 1, 1997, GAF effected a series of
          transactions that resulted in, among other things, the capital stock
          of the Registrant being distributed to the stockholders of GAF.  As a
          result of such distribution, the Registrant and its principal asset,
          which is approximately 84% of the issued and outstanding shares of
          capital stock of International Specialty Products Inc. ("ISP"), are
          no longer direct or indirect assets of GAF or its subsidiary, G-I
          Holdings, while Building Materials Corporation of America and U.S.
          Intec, Inc. and certain other assets and liabilities, including
          liabilities for asbestos-related claims, remain part of G-I Holdings
          and GAF, but are not assets or liabilities of the Company.

NOTE B:   Inventories consist of the following:

                                         December 31,   Sept. 28,
                                             1996          1997
                                         ------------   ---------
                                                 (Thousands)
             
             Finished goods                $ 68,436     $ 77,638
             Work in process............     24,261       19,923
             Raw materials and supplies      17,814       19,614
                                           --------     --------
             Total......................    110,511      117,175
             Less LIFO reserve..........     (1,925)      (4,150)
                                           --------     --------
             Inventories................   $108,586     $113,025
                                           ========     ========










                                       4
<PAGE>
            NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued)


NOTE C:   Contingencies


          Asbestos Litigation Against GAF

               GAF is a defendant in a substantial number of pending lawsuits
          involving asbestos-related bodily injury claims.  GAF and G-I
          Holdings have established reserves for such claims based on certain
          assumptions, one of which was the effectiveness of a class action
          settlement of future asbestos-related bodily injury claims (the
          "Settlement").  On June 25, 1997, the United States Supreme Court
          affirmed the ruling of the United States Court of Appeals for the
          Third Circuit that the class in such action was not certifiable, thus
          rendering the Settlement inoperable.  GAF and G-I Holdings have
          advised the Company that they are presently evaluating the effect of
          this Supreme Court decision on the amount of their reserves for
          asbestos-related liabilities, that such analysis could result in GAF
          and G-I Holdings increasing their estimates of asbestos-related
          liabilities, and that it is not currently possible to estimate the
          range or amount, if any, of such possible additional reserves.  GAF
          and G-I Holdings have stated that they remain committed to
          effectuating a comprehensive resolution of asbestos-related bodily
          injury claims, that they are presently exploring a number of options,
          both judicial and legislative, to accomplish such resolution, but
          that there can be no assurance that these efforts will be successful.

               Neither ISP, the Registrant nor the assets or operations of ISP,
          which was operated as a division of a corporate predecessor of GAF
          prior to July 1986, have been involved in the manufacture or sale of
          asbestos products.  The Company believes that it and ISP should have
          no legal responsibility for damages in connection with asbestos-
          related claims.

               For further information regarding asbestos-related matters,
          reference is made to Note 13 to Consolidated Financial Statements
          contained in the Form S-4.


          Environmental Litigation


               The Company, together with other companies, is a party to a
          variety of administrative proceedings and lawsuits involving
          environmental matters ("Environmental Claims"), in which recovery is
          sought for the cost of cleanup of contaminated sites, a number of
          which Environmental Claims are in the early stages or have been
          dormant for protracted periods.






                                       5
<PAGE>
            NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (Continued)


NOTE C:   (Continued)


               In the opinion of the Company's management, the resolution of
          the Environmental Claims should not be material to the business,
          liquidity, results of operations, cash flows or financial position of
          the Company.  However, adverse decisions or events, particularly as
          to the liability and the financial responsibility of the Company's
          insurers and of the other parties involved at each site and their
          insurers, could cause the Company to increase its estimate of its
          liability in respect of such matters.  It is not currently possible
          to estimate the amount or range of any additional liability.

               For further information regarding environmental matters,
          reference is made to "Business - Environmental Litigation" contained
          in the Form S-4.


          Tax Claim Against GAF

               On September 15, 1997, GAF received a notice from the Internal
          Revenue Service (the "Service") of a deficiency in the amount of
          $84.4 million (after taking into account the use of net operating
          losses and foreign tax credits otherwise available for use in later
          years) in connection with the formation in 1990 of Rhone-Poulenc
          Surfactants and Specialties, L.P. (the "surfactants partnership"), a
          partnership in which a subsidiary of GAF, GAF Fiberglass Corporation
          ("GFC"), holds an interest.  The claim of the Service for interest
          and penalties, after taking into account the effect on the use of net
          operating losses and foreign tax credits, could result in GFC
          incurring liabilities significantly in excess of the deferred tax
          liability of $131.4 million that GAF recorded in 1990 in connection
          with this matter.  GAF has advised the Company that it believes that
          GFC will prevail in this matter, although there can be no assurance
          in this regard.  The Company believes that the ultimate disposition
          of this matter will not have a material adverse effect on its
          financial position or results of operations.  GAF, G-I Holdings and
          certain subsidiaries of GAF have agreed to jointly and severally
          indemnify the Company against any tax liability associated with the
          surfactants partnership, which the Company would be severally liable
          for, together with GAF and several subsidiaries of GAF, should GAF
          and cetain of its subsidiaries be unable to satisfy such indemnity.











                                       6
<PAGE>
          Item 2.   MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL
                      CONDITION AND RESULTS OF OPERATIONS


Results of Operations - Third Quarter 1997 Compared With
                        Third Quarter 1996


     The Company recorded third quarter 1997 income from continuing operations
of $14.4 million versus $16.7 million in the third quarter of 1996.  The
decrease was attributable to increased interest expense resulting from the
issuance of $524.9 million of the Registrant's senior debt in October 1996,
partially offset by higher operating and other income.

     Net sales for the third quarter of 1997 were $183.6 million, a 6% increase
compared with $173.6 million for the third quarter of 1996.  The higher sales
reflected higher sales of specialty chemicals (up $13.6 million) as a result of
increased sales volumes (up $22.8 million), partially offset by the unfavorable
effect of the stronger U.S. dollar relative to other currencies in certain
areas of the world ($6.6 million), and, to a lesser extent, by unfavorable
selling prices.  Partially offsetting the increased sales of specialty
chemicals were lower sales of mineral products and filter products, down $2.2
and $1.3 million, respectively, primarily as a result of lower sales volumes.
The sales growth in the third quarter reflected increased sales in the U.S.,
the Asia-Pacific region and the Western Hemisphere, partially offset by lower
sales in Europe due primarily to the effect of the stronger U.S. dollar.

     Operating income for the third quarter of 1997 increased to $34.6 million
from last year's $33.5 million.  The increase in operating income reflected
improved income from specialty chemicals (up $2.3 million) as a result of the
increased sales, partially offset by the impact of the stronger U.S. dollar and
lower mineral products results (down $0.7 million).

     Interest expense for the third quarter was $18.0 million compared with
$7.0 million in the third quarter of 1996.  The higher interest expense was
attributable to higher debt levels.  Other income, net, for the third quarter
of 1997 was $10.4 million compared with $3.0 million in the third quarter of
1996, due principally to higher investment income.


Results of Operations - Nine Months 1997 Compared With
                        Nine Months 1996

     For the first nine months of 1997, the Company recorded income from
continuing operations of $41.1 million compared with $51.8 million for the
first nine months of 1996.  The decrease was attributable to increased interest
expense resulting from the issuance of $524.9 million of the Registrant's
senior debt in October 1996, partially offset by higher operating and other
income.





                                       
                                       
                                       7
<PAGE>
     Net sales for the first nine months of 1997 were $572.6 million versus net
sales of $544.1 million for the same period in 1996.  The higher sales were
attributable to increased sales of specialty chemicals (up $28.9 million) as a
result of increased sales volumes (up $54 million), partially offset by the
unfavorable effect of the stronger U.S. dollar relative to other currencies in
certain areas of the world ($16.6 million), and by unfavorable pricing.  The
sales growth reflected sales increases in the U.S., the Asia-Pacific region and
the Western Hemisphere, partially offset by lower sales in Europe due primarily
to the effect of the stronger U.S. dollar.

     Operating income for the first nine months of 1997 was $110 million
compared with the $105.7 million recorded in the first nine months of 1996.
The higher operating income reflected improved results in all business
segments, principally specialty chemicals (up $2.5 million due to the higher
sales) and filter products (up $2.1 million primarily due to favorable
pricing), partially offset by the effects of the stronger U.S. dollar in
certain areas of the world.

     Interest expense for the first nine months of 1997 was $55.5 million
compared with $21.9 million for the same period in 1996.  The higher interest
expense was primarily attributable to higher debt levels.  Other income, net,
for the first nine months of 1997 was $23.8 million compared with $9.4 million
last year, with the increase resulting primarily from higher investment income.


Liquidity and Financial Condition


     During the first nine months of 1997, the Company generated cash from
operations of $68.4 million, reinvested $45.8 million for capital programs and
generated $27.1 million from net sales of available-for-sale and held-to-
maturity securities, for a net cash inflow of $49.6 million before financing
activities.  Cash from operations reflected a $36.1 million cash outlay for net
purchases of trading securities and also included $6.3 million of dividends
received from the GAF-Huls Chemie GmbH joint venture.  Working capital
increased by $6.7 million, primarily reflecting a $9.5 million increase in
trade accounts receivable due to higher sales in September 1997 versus December
1996, a $10.1 million increase in accounts receivable, other, mainly from the
sale of ISP's domestic trade accounts receivable, and a $4.4 million increase
in inventories, partially offset by a $21.4 million increase in accounts
payable and accrued liabilities.

     Net cash used in financing activities in the first nine months of 1997
totaled $37.8 million, mainly reflecting a $21.4 million decrease in borrowings
under ISP's bank revolving credit facility, a $5.7 million reduction in short-
term borrowings and $10.2 million of repurchases of ISP's common stock pursuant
to ISP's repurchase program.

     As a result of the foregoing factors, cash and cash equivalents increased
by $11.8 million during the first nine months of 1997 to $29.8 million
(excluding $191.7 million of trading, available-for-sale and held-to-maturity
securities and other short-term investments).




                                       8
<PAGE>
     The Registrant is a holding company without independent businesses or
operations and, as such, is dependent upon the cash flow of its approximately
84%-owned subsidiary, ISP, in order to satisfy its obligations.  The Registrant
expects to satisfy such obligations from, among other things, refinancings of
debt, dividends and loans from ISP, as to which there are restrictions under
ISP's revolving credit facility and the indenture relating to ISP's 9% Senior
Notes, and payments pursuant to the Tax Sharing Agreement between the
Registrant and ISP.  As of September 28, 1997, it would have been permissible
for ISP to pay dividends in the aggregate amount of $102.8 million, of which
$86.3 million would have been available to the Registrant, and to make loans to
affiliates of $75 million.  In addition, as of September 28, 1997, loans in the
aggregate amount of $59.3 million were owed by ISP to the Registrant.

     See Note C to Consolidated Financial Statements for information regarding
contingencies.









































                                       9
<PAGE>
                                    PART II
                                       
                                       
                               OTHER INFORMATION


Item 6.  Exhibits and Reports on Form 8-K

(a)  Exhibits

     27 - Financial Data Schedule, which is submitted electronically to the
          Securities and Exchange Commission for information only.

(b)  No Reports on Form 8-K were filed during the quarter ended
     September 28, 1997.









































                                      10
<PAGE>
                                  SIGNATURES
                                  -----------



     Pursuant to the requirements of Section 13 or 15(d) 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.


                               ISP HOLDINGS INC.
                               


DATE:  November 12, 1997          BY:  /s/James P. Rogers
       -----------------               --------------------------
                                      James P. Rogers
                                      Executive Vice President and
                                       Chief Financial Officer
                                      (Principal Financial Officer)




DATE:  November 12, 1997          BY:  /s/Jonathan H. Stern
       -----------------               ------------------------------
                                       Jonathan H. Stern
                                       Vice President and Controller
                                       (Principal Accounting Officer)



























                                      11