<PAGE>
 
                                 UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                              Washington, DC 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 March 31, 1999

                                       OR

[ ]  TRANSITION REPORT UNDER SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT
     OF 1934

     For the transition period from ________ to ________


                      Commission file number  333-60575
                                             -------------

                      INTEREP NATIONAL RADIO SALES, INC.
------------------------------------------------------------------------------
             (Exact name of registrant as specified in its charter)

           New York                            13-1865151
------------------------------------------------------------------------------
(State or other jurisdiction of              (I.R.S. Employer
incorporation or organization)                Identification No.)

100 Park Avenue, New York, New York                10017
------------------------------------------------------------------------------
(Address of principal executive offices)        (Zip Code)

                                  (212) 916-0700
------------------------------------------------------------------------------
              (Registrant's telephone number, including area code)

    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 May 10, 1999, there were 297,976 outstanding shares of the
registrant's Common Stock, $0.04 par value per share.
<PAGE>
 
                         PART I.  FINANCIAL INFORMATION


Item 1.   FINANCIAL STATEMENTS

                       INTEREP NATIONAL RADIO SALES, INC.

                          CONSOLIDATED BALANCE SHEETS
                    (in thousands except share information)
                                  (Unaudited)

<TABLE>
<CAPTION>
                                                                          March 31,   December 31,
                                                                             1999         1998
                                                                          ----------  -------------
                                              ASSETS

<S>                                                                       <C>         <C>
Current assets:
Cash and cash equivalents                                                  $ 23,216       $ 32,962
Receivables, less allowance for doubtful accounts of $1,584 and $1,626       27,041         35,104
 respectively
Representation contract buyouts receivable                                   10,251         11,447
Current portion of deferred representation contract costs                    30,405         33,742
Prepaid expenses and other current assets                                     1,906          1,207
                                                                           --------       --------
Total current assets                                                         92,819        114,462
                                                                           --------       --------
 
Fixed assets, net                                                             5,140          4,311
Deferred costs on representation contract purchases                          43,893         45,702
Station contract rights, net                                                  1,427          1,681
Representation contract buyouts receivable                                    5,421          6,920
Other assets                                                                 11,409         11,432
                                                                           --------       --------
Total assets                                                               $160,109       $184,508
                                                                           ========       ========
</TABLE> 


                                      -2-
<PAGE>
<TABLE> 
<CAPTION> 
                                                                          March 31,   December 31,
                                                                            1999          1998
                                                                           --------      --------
<S>                                                               <C>                 <C> 
LIABILITIES AND SHAREHOLDERS' DEFICIT

Current liabilities:
Capitalized lease obligations                                              $     52       $    103
Accounts payable and accrued expenses                                        12,054         16,537
Accrued interest                                                              2,500          4,972
Representation contract buyouts payable                                      18,499         20,219
Accrued employee-related liabilities                                          3,044          6,520
                                                                           --------       --------
Total current liabilities                                                    36,149         48,351
                                                                           --------       --------
Long-term debt                                                              100,000        100,000
                                                                           --------       --------
Representation contract buyouts payable                                      22,917         26,706
                                                                           --------       --------

 
Other noncurrent liabilities                                                  7,654         16,150
                                                                           --------       --------
 
Commitments and contingencies
Total common and preferred stock subject to redemption                            -              -
Shareholders' deficit:
Common stock, $.04 par value-1,000,000 shares authorized, 334,549                             
 shares issued                                                                   14             14
Additional paid-in-capital                                                    1,163          1,163
Accumulated deficit                                                          (5,697)        (5,797)
Receivable from Employee Stock Ownership Plan                                   (82)           (82)
Treasury stock, at cost-36,724 and 36,573 shares, respectively               (2,009)        (1,997)
                                                                           --------       --------
Total shareholders' deficit                                                  (6,611)        (6,699)
                                                                           --------       --------
Total liabilities and shareholders' deficit                                $160,109       $184,508
                                                                           ========       ========
</TABLE>

                                      -3-
<PAGE>
 
                       INTEREP NATIONAL RADIO SALES, INC.

                     CONSOLIDATED STATEMENTS OF OPERATIONS
                                 (in thousands)
                                  (unaudited)

 
<TABLE>
<CAPTION>
                                                          For the
                                                       Three Months
                                                      Ended March 31,
                                                     -----------------
                                                       1999     1998
                                                     --------  -------
 
<S>                                                  <C>       <C>
Commission revenue                                   $17,511   $15,898
Contract termination revenue                           2,505    24,116
                                                     -------   -------
 
Total revenues                                        20,016    40,014
                                                     -------   -------
 
Operating expenses:
Selling expenses                                      14,646    13,836
General and administrative expenses                    2,599     2,597
Depreciation and amortization expense                  9,502     9,096
                                                     -------   -------
 
Total operating expenses                              26,747    25,529
                                                     -------   -------
 
Operating (loss) income                               (6,731)   14,485
Interest expense, net                                  2,382     1,005
                                                     -------   -------
 
(Loss) Income before (benefit) provision for         
income taxes                                          (9,113)   13,480
(Benefit) provision for income taxes                  (3,736)    5,526     
                                                     -------   -------
 
Net (loss) income                                     (5,377)    7,954
                                                     -------   -------
 
Preferred stock dividend requirements and                  -       465
redemption premium                                   -------   -------
 
 
Net (loss) income applicable to common shareholders  $(5,377)  $ 7,489
                                                     =======   =======
</TABLE>

                                      -4-
<PAGE>
 
                       INTEREP NATIONAL RADIO SALES, INC.

                     CONSOLIDATED STATEMENTS OF CASH FLOWS
                                 (in thousands)
                                  (unaudited)


<TABLE>
<CAPTION>
                                                                       For the
                                                                     Three Months
                                                                   Ended March 31,
                                                                  ------------------
                                                                    1999      1998
                                                                  --------  --------
 
Cash flows from operating activities:
<S>                                                               <C>       <C>
Net (loss) income                                                 $(5,377)  $ 7,954
Adjustments to reconcile (loss) income to net cash provided by
 operating activities:
Depreciation and amortization                                       9,502     9,096
Changes in assets and liabilities-                                 
Receivables                                                         8,063     2,967     
Representation contracts buyout receivable                          2,695    (9,175)
Prepaid expenses and other current assets                            (699)     (254)
Other noncurrent assets                                              (236)     (116)
Accounts payable and accrued expenses                              (4,534)   (2,049)
Accrued interest                                                   (2,472)      (71)
Accrued employee-related liabilities                               (3,476)   (1,806)
Other noncurrent liabilities                                       (3,019)    5,744
                                                                  -------   -------
 
Net cash provided by operating activities                             447    12,290
                                                                  -------   -------
 
Cash flows from investing activities:
Additions to fixed assets                                          (1,155)     (177)
                                                                  -------   -------
 
Net cash used in investing activities:                             (1,155)     (177)
                                                                  -------   -------
 
Cash flows from financing activities:
Station representation contracts payments                          (9,026)   (7,294)
Debt repayments                                                         -    (7,250)
Borrowings in accordance with credit agreement                          -     5,725
Purchases of treasury stock                                           (12)     (256)
Other, net                                                              -       (16)
                                                                  -------   -------
 
Net cash used in financing activities                              (9,038)   (9,091)
                                                                  -------   -------
 
Net (decrease) increase in cash and cash equivalents               (9,746)    3,022
Cash and cash equivalents, beginning of period                     32,962     1,419
                                                                  -------   -------
 
Cash and cash equivalents, end of period                          $23,216   $ 4,441
                                                                  =======   =======
 
Supplemental disclosures of cash flow information:
Cash paid during the year for:
   Interest paid                                                  $ 4,972   $   904
   Income taxes paid                                                  403        49
Non-cash investing and financing activities:
   Station representation contracts acquired                      $ 2,919   $ 2,597
                                                                  =======   =======
</TABLE>

                                      -5-
<PAGE>
 
                       INTEREP NATIONAL RADIO SALES, INC.

          NOTES TO UNAUDITED INTERIM CONSOLIDATED FINANCIAL STATEMENTS
                    (in thousands except share information)

1.   Summary of Significant Accounting Policies

Principles of Consolidation

          The consolidated financial statements include the accounts of Interep
National Radio Sales, Inc. ("Interep"), together with its subsidiaries
(collectively, the "Company") and have been prepared in accordance with the
rules and regulations of the Securities and Exchange Commission. Accordingly,
certain information and footnote disclosures normally included in financial
statements prepared in accordance with generally accepted accounting principles
have been condensed or omitted. All significant intercompany transactions and
balances have been eliminated.

          The consolidated financial statements of March 31, 1999 and 1998 are
unaudited; however, in the opinion of management, such statements include all
adjustments necessary for a fair presentation of the results for the periods
presented.  The interim financial statements should be read in conjunction with
the audited financial statements and notes thereto included in the Company's
Consolidated Financial Statements for the year ended December 31, 1998, which
are available upon request of the Company.  Due to the seasonal nature of the
Company's business, the results of operations for the interim periods are not
necessarily indicative of the results that might be expected for future interim
periods or for the full year ended December 31, 1999.

Revenue Recognition

          The Company is a national representation ("rep") firm serving radio
broadcast clients throughout the United States. Commission revenue is derived
from sales of advertising time for radio stations under representation
contracts.  Commissions and fees are recognized in the month the advertisement
is broadcast. In connection with its unwired network business, the Company
collects fees for unwired network radio advertising and, after deducting its
commissions, remits the fees to the respective radio stations. Since it is
common practice in the industry for rep companies not to pay a station until the
corresponding receivable is paid, and since the receivable and payable are
equal, except for the commissions, fees payable to stations have been offset
against the related receivable from advertising agencies in the accompanying
consolidated balance sheets.

Representation Contract Termination Revenue and Contract Acquisition Costs

          The Company's station representation contracts usually renew
automatically from year to year unless either party provides written notice of
termination at least twelve months prior to the next automatic renewal date. In
accordance with industry practice, in lieu of termination, an arrangement is
normally made for the purchase of such contracts by a successor representation
firm. The purchase price paid by the successor representation firm is generally
based upon the historic commission income projected over the remaining contract
period, plus two months (the "Buyout Period").

          Costs of obtaining station representation contracts are deferred and
amortized over the Buyout Period.  Such amortization is included in the
accompanying consolidated statements of operations as a component of
depreciation and amortization expense. Amounts which are to be amortized during
the next year are included as current assets in the accompanying consolidated
balance sheets.  Income earned from the loss of station representation contracts
(contract termination revenue) is recognized on the effective date of the buyout
agreement.

                                      -6-
<PAGE>
 
          In addition, costs incurred as a result of commission rate reductions
are deferred and amortized over the remaining life of the existing
representation agreement. Such amortization is included in the accompanying
consolidated statements of operations as a component of depreciation and
amortization expense.

2.   New Accounting Pronouncements

          In June 1998, the Financial Accounting Standards Board issued
Statement of Financial Accounting Standards No. 133, "Accounting for Derivative
Instruments and Hedging Activities" ("SFAS 133").  The Statement establishes
accounting and reporting standards requiring that every derivative instrument be
recorded in the balance sheet and measured at its fair value.  This Statement
also requires that changes in the derivative's fair value be recognized
currently in earnings.  To date, the Company has not, and has no present
intention, to invest in any derivative instruments or participate in any hedging
activities.  Accordingly, the adoption of SFAS 133 will not have any effect on
the Company.

3.   Segment Disclosures

          In 1998, the Company adopted Statement of Financial Accounting
Standards No. 131, "Disclosure about Segments of an Enterprise and Related
Information". The Statement requires the Company to report segment financial
information consistent with the presentation made to the Company's management
for decision making purposes. The Company is managed as one segment and all
revenues are derived solely from radio representation operations and related
activities. The Company's management decisions are based on EBITDA (income
before interest, taxes, depreciation and amortization) of $2,771 and $23,581 
in the quarters ended March 31, 1999 and 1998, respectively.
 

                                      -7-
<PAGE>
 
Item 2.   MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL
          CONDITION AND RESULTS OF OPERATIONS

          The following discussion is based upon and should be read in
conjunction with the Consolidated Financial Statements, including the notes
thereto, included elsewhere in this Report.

          Certain statements contained herein, including without limitation,
statements containing the words "believes", "anticipates", "intends", "expects"
and words of similar import, constitute "forward-looking statements." Such
forward-looking statements involve known and unknown risks, uncertainties and
other factors that may cause the actual results, performance or achievements of
the Company or industry results to be materially different from any future
results, performance or achievements expressed or implied by such forward-
looking statements. Such factors include, among others, the following: general
economic and business conditions, both domestic and foreign; industry capacity;
demographic changes; existing government regulations and changes in, or the
failure to comply with, government regulations; liability and other claims
asserted against the Company; competition; the loss of any significant
customers; changes in operating strategy or development plans; the ability to
attract and retain qualified personnel; the significant indebtedness of the
Company after certain financing transactions in 1998; and other factors
referenced in this Report. Given these uncertainties, prospective investors are
cautioned not to place undue reliance on such forward-looking statements. The
Company disclaims any obligation to update any such factors or to publicly
announce the result of any revisions to any of the forward-looking statements
contained herein to reflect future events or developments.

General

          The Company derives substantially all of its revenues from commissions
on sales of national spot radio advertising air time on behalf of radio stations
represented by the Company. Generally, national spot advertising time is
purchased by advertising agencies or media buying services retained by
advertisers to create advertising campaigns and to place advertising with radio
stations and other media. The Company receives commissions from its client radio
stations based on the national spot radio advertising billings of the station,
net of the standard advertising agency and media buying services commissions
(typically 15%). Commission rates are negotiated and set forth in a client's
representation contract. Since commissions are based on the prices paid to radio
stations for spots, the Company's revenue base is constantly adjusted for
inflation.

          The Company's operating results generally are dependent on (i)
increases and decreases in the size of the total national spot radio advertising
market, (ii) changes in the Company's share of this market, (iii) acquisitions
and terminations of representation contracts and (iv) the Company's operating
expense levels. The effect of these factors on the Company's financial condition
and results of operations has varied from period to period.

          Total United States national spot radio advertising annual revenues
have grown from approximately $1.1 billion to approximately $2.0 billion during
the six years ended December 31, 1998. The performance of the national spot
radio advertising market is influenced by a number of factors, including, but
not limited to, general economic conditions, consumer attitudes and spending
patterns, the share of total advertising spent on radio and the share of total
radio advertising represented by national spot radio.

          The Company's share of the national spot advertising market changes as
a result of increases and decreases in the amount of national spot advertising
broadcast on the Company's client stations. Moreover, the Company's market share
increases as the Company acquires representation contracts with new client
stations, and decreases if current client station representation contracts are
terminated. Thus, the Company's ability to attract new clients, while retaining
existing clients, significantly affects its market share. In this regard, the
value of representation contracts which have been acquired or terminated during
the last few years has tended to increase, due to a number of factors, including
the consolidation of ownership 

                                      -8-
<PAGE>
 
in the radio broadcast industry following the enactment of the
Telecommunications Act of 1996. Accordingly, in recent years, the Company's rep
contract acquisition activity has increased and the Company has devoted a
significant amount of its resources to acquiring representation contracts. At
the same time, there has been an increase in the amount of revenue received by
the Company on the termination of representation contracts. The decision to
acquire a representation contract is based on the market share opportunity
presented and an analysis of the costs and net benefits to be derived. The
Company continuously seeks opportunities to acquire additional representation
contracts on attractive terms, while maintaining its current clients. The
Company's ability to acquire and maintain representation contracts has had, and
will continue to have, a significant impact on its revenues and cash flows.

          Following industry practice, the Company acts as the exclusive
national rep firm for each of its client radio stations pursuant to a written
contract. If a station terminates its contract prior to the scheduled
termination date, the station is obligated to pay the Company, as required by
the contract or in accordance with industry practice, an amount approximately
equal to the commissions the Company would have earned during the unexpired term
of the canceled contract, plus an additional two months of "spill over"
commissions (representing commissions earned on advertising placed or committed
to prior to the contract termination but broadcast thereafter). In practice,
these amounts are usually paid by the successor rep firm which signs a new
contract with the station and assumes the responsibility for payment to the
former rep firm. Such payments are usually made in equal monthly installments
over a period consisting of one-half the number of months remaining under the
terminated contract. For example, if the Company acquires the representation
contract of a station which is terminating its contract with a competing rep
firm with a remaining unexpired term of 12 months, the total obligation would be
14 months of commissions payable in seven equal monthly installments.

          The Company recognizes revenue resulting from the termination of a
contract with a client as of the effective date of the termination. In this
regard, when a contract is terminated, the unamortized portion, if any, of the
expense originally incurred on acquisition of such contract is written-off
entirely. Historically, these amounts have not been material. With respect to
its entry into a representation contract with a new client, the Company
amortizes the contract acquisition cost incurred in equal monthly installments
over the life of the new contract. As a result, the Company's operating income
is affected, negatively or positively, by the acquisition or loss of client
stations.

          The Company has been unable to identify a method to forecast any
trends in buyout activity, or in the amount of revenue or expense that will
likely be associated with buyouts during a particular period. Generally, the
amount of revenue resulting from the buyout of a representation contract depends
on the length of the remaining term of the contract and the revenue generated
under the contract during the 12 months preceding the date of termination (the
"trailing period"). The amount recognized by the Company as contract termination
revenue in any period is not, however, indicative of such revenue that may be
realized in any future period from contract terminations because historically
the level of buyout activity has varied from period to period and because the
length of the remaining terms, and the commission revenue generation, of the
contracts which are terminated in any period vary to a considerable extent.
Accordingly, while the consolidation of ownership in the radio broadcast
industry that has followed the enactment of the Telecommunications Act of 1996
has increased buyout activity and amounts, the impact of such activity on the
Company's revenues and income is expected to be uncertain, due to the variables
of contract length and commission generation.

          While the commission revenue generated under a representation contract
during a trailing period is used in the calculation of the payments to be made
by the Company on its acquisition of such contract, such revenue should not be
relied on as an indication of the future commission revenue to be generated by
the Company under that contract. Such revenue will depend on a number of
factors, including the amount of national spot advertising broadcast by the
station involved. This, in turn, will be affected by factors such as general and
local economic conditions, consumer attitudes and spending patterns, the share
of total advertising spent on radio and the share of total radio advertising
represented by national spot radio.

                                      -9-
<PAGE>
 
          The Company's selling and corporate expense levels are dependent on
management decisions regarding operating and staffing levels and on inflation.
Selling expenses represent all costs associated with the Company's marketing,
sales and sales support functions. Corporate expenses include items such as
corporate management, corporate communications, financial services, advertising
and promotion expenses, Internet representation development expenses and
employee benefit plan contributions.

          The Company's business normally follows the pattern of advertising
expenditures in general and is seasonal to the extent that radio advertising
spending increases during the fourth calendar quarter in connection with the
Christmas season and tends to be weaker during the first calendar quarter. Radio
advertising generally increases during the second and third quarters due to
holiday-related advertising, school vacations and back-to-school sales.
Additionally, radio tends to experience increases in the amount of advertising
revenues as a result of special events such as Presidential election campaigns.
Furthermore, the level of advertising revenues of radio stations, and therefore
the level of revenues of the Company, is susceptible to prevailing general and
local economic conditions and the corresponding increases or decreases in the
budgets of advertisers, as well as market conditions and trends affecting
advertising expenditures in specific industries.

Results of Operations

Three Months Ended March 31, 1999 Compared to Three Months Ended March 31, 1998

          Commission Revenue.   Commission revenue in the first quarter of 1999
increased to $17.5 million, approximately 10.1%, from $15.9 million in the
comparable quarter in 1998.  This increase is attributable to the fact that
commissions generated from new client representation contracts (primarily the
ABC radio stations) exceeded the loss of commission revenue from terminated
representation contracts (primarily Nationwide Communications), as well as a
general increase in national spot advertising on client stations.

          Contract Termination Revenue.  Contract termination revenue was $2.5
million during the first quarter of 1999, as compared to $24.1 million in the
comparable 1999 period, a decrease of $21.6 million, or 89.6%.  This difference
is attributable to the fact that a substantial amount of contract termination
revenue was generated in the first quarter of 1998 as a result of the
termination of the Company's representation contracts with stations owned by SFX
Broadcasting, Inc., when SFX was acquired by an affiliate of a competitor of the
Company. The loss of representation contracts during the first quarter of 1999
was not as significant.  The value of representation contracts acquired or
terminated during the last few years has generally tended to increase, due to a
number of factors, including the consolidation of ownership in the radio
broadcast industry following the enactment of the Telecommunications Act of
1996.

          Selling Expenses.  Selling expenses for the first three months of 1999
increased to $14.6 million from $13.8 million during the same period of 1998.
This increase of $0.8 million, or approximately 5.9%, was primarily due to
employee compensation increases associated with the growth in commission
revenue.

          General and Administrative Expenses.  General and administrative
expenses were virtually unchanged at $2.6 million for the first quarter of 1999
and 1998.  The benefits of the Company's back office relocation were offset by
costs incurred in connection with the Company's entry into Internet
representation.

          Depreciation and Amortization.   Depreciation and amortization
increased by $0.4 million in the first quarter of 1999, to $9.5 million, from
$9.1 million in the first quarter of 1998.  This increase of approximately 4.5%
was due to the amortization of new representation contracts.

          Operating Income.  Operating income decreased by $21 million, or
146.5%, for the first quarter of 1999, compared with the comparable period in
1998.  This decline is essentially attributable to the reduction in contract
termination revenue.

                                      -10-
<PAGE>
 
          Interest Expense, net.  Interest expense, net increased approximately
$1.4 million, or approximately 137%, to $2.4 million for the first quarter of
1999, compared to $1.0 million for the first quarter of 1998.  This increase
primarily resulted from the interest on the $100.0 million principal amount of
10% Senior Subordinated Notes due 2008 issued by the Company on July 2, 1998.

          (Benefit) Provision for Income Taxes.    Benefit for income taxes was
approximately $3.7 million for the first quarter of 1999 compared to a provision
for income taxes of $5.5 million in the comparable 1998 period, as the loss
incurred during the quarter generated a credit which will be applied against
income earned later in the year.

          Net Income (Loss).  The Company's net loss after tax of approximately
$5.3 million for the three months ended March 31, 1999, a $13.3 million
reduction from the $7.9 million net income for the comparable period in 1998, is
essentially attributable to the reduction in contract termination revenue
discussed above.  It also reflects the fact that, due to the seasonality of the
Company's business, the first quarter is the normally the Company's weakest
quarter.

Liquidity and Capital Resources

          The Company's cash requirements have been primarily funded by cash
provided from operations and bank debt.  Cash provided by operating activities
for the quarter ended March 31, 1999 amounted to $0.4 million.  As noted above,
the first quarter is the Company's weakest quarter due to seasonality.

          Net cash used in investing activities is attributable to capital
expenditures. Capital expenditures of $1.2 million during the first quarter of
1999 were primarily for computer equipment and upgrades.

          Overall cash used for financing activities of $9.0 million during the
first quarter of 1999 was primarily used for acquisitions of station
representation contracts.

          In general, as the Company acquires new representation contracts, it
uses more cash and, as its contracts are terminated, it receives additional
cash. For the reasons noted in "General" above, the Company is not able to
predict the amount of cash it will require for contract acquisitions, or the
cash it will receive on contract terminations, from period to period. The
Company believes, however, that based on its historical performance, it will
generate sufficient cash from operations and borrowings to fund its foreseeable
contract acquisition payment requirements.

          On July 2, 1998, the Company issued $100.0 million aggregate principal
amount of 10% Senior Subordinated Notes due July 1, 2008 (the "Notes").  A
portion of the net proceeds of this issuance was used to repay the then
outstanding balance of the Company's bank debt.  Additionally, the Company
redeemed all of the outstanding shares of the Company's Series A Preferred Stock
and Series B Preferred Stock, together with all of the outstanding shares of
Common Stock subject to redemption.  The Company also entered into an agreement
with two banks to provide the Company with a $10.0 million revolving credit
facility.

          The Company believes that its enhanced liquidity resulting from the
transactions described above, together with anticipated cash from continuing
operations, should be sufficient to fund its operations and anticipated needs
for required representation contract acquisition payments, and to make required
payments of principal and interest under its new credit facility and 10.0%
annual interest payments on the Notes.  The Company may not, however, generate
sufficient cash flow for these purposes or to repay the Notes at maturity.  The
Company's ability to fund its operations and required contract buyout payments
and to make scheduled principal and interest payments will depend on its future
performance, which, to a certain 

                                      -11-
<PAGE>
 
extent, is subject to general economic, financial, competitive, legislative,
regulatory and other factors that are beyond its control. The Company may also
need to refinance all or a portion of the Notes on or prior to maturity. There
can be no assurance that the Company will be able to effect any such refinancing
on commercially reasonable terms or at all.

Year 2000 Assessment

          Many computer systems experience problems handling dates beyond the
year 1999. Therefore, some computer hardware and software will need to be
modified prior to the year 2000 in order to remain functional. During 1998, the
Company completed an assessment of its internal readiness to implement Year 2000
compliant systems on a timely basis. The Company currently utilizes software
systems for its accounting, billing and database management functions, among
others, which were developed by third parties or developed by the Company using
third party software development tools. These third parties have advised the
Company that such systems are Year 2000 compliant or, in some cases, will be
made Year 2000 compliant through the installation of software patches or
upgrades.  The Company completed implementation of programming changes needed to
make its systems Year 2000 compliant during the first quarter of 1999 and does
not believe that the related cost will have a material adverse effect on the
Company. The Company estimates that its expenditures for Year 2000 compliance
implementation during 1999 could be $250,000. There can be no assurance,
however, that there will not be a delay in, or increased costs associated with,
the implementation of such changes, and any inability to implement such changes
could have a material adverse effect on the Company.

          The Company has not completed its assessment of the Year 2000
compliance of its radio station clients, nor of the possible consequences to the
Company of the failure of one or more of its radio station clients to become
Year 2000 compliant on a timely basis.  It is possible that if a substantial
number of the Company's radio station clients failed to implement Year 2000
compliant billing or payment systems, for example, their payments to the Company
of commissions on the sale of radio advertising time might be disrupted, which
might adversely affect the Company's cash flow. The Company will discuss these
matters with its key radio station clients during 1999 to attempt to ascertain
whether and to what extent such problems are likely to occur.  It is not clear,
however, what measures (if any) the Company could take to deal with such
eventualities while still maintaining client relationships.  The Company has
been advised by its principal suppliers of data base information services and
payroll services that those services will be Year 2000 compliant on a timely
basis.  The Company does not believe that it has other relationships with
vendors or suppliers which, if disrupted due to the failure of such vendors and
suppliers to deal adequately with their own Year 2000 compliance issues, would
have a material adverse effect on the Company.


Item 3.   QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK
 
          The Company is exposed to market risk from changes in interest rates
that may adversely affect its results of operations and financial condition.
The Company seeks to minimize the risks from these interest rate fluctuations
through its regular operating and financing activities.  The Company's policy is
not to use financial instruments for trading or other speculative purposes.  The
Company is not currently a party to any financial instruments.
 


                          PART II.  OTHER INFORMATION


Item 6.   EXHIBITS AND REPORTS ON FORM 8-K

                                      -12-
<PAGE>
 
     (a) Exhibits.  The Exhibits filed with this Report are listed on the
Exhibit Index immediately following the signature page.

     (b) Reports on Form 8-K.  No Reports on Form 8-K were filed during the
three months ended March 31, 1999.

                                      -13-
<PAGE>
 
                                   SIGNATURES

          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.

                                    INTEREP NATIONAL RADIO SALES, INC.


May 17, 1999                        By         WILLIAM J. McENTEE, JR.
                                      ----------------------------------------
                                         William J. McEntee, Jr.
                                         Vice President and
                                         Chief Financial Officer

                                      -14-
<PAGE>
 
                                 EXHIBIT INDEX


10.1  Amendment to Revolving Line of Credit Agreement, dated as of April 30,
      1999, among the Registrant, its subsidiaries, BankBoston, N.A., and Summit
      Bank

27.1  Financial Data Schedule