<PAGE>

                                                                    EXHIBIT 10.1

                      AMENDMENT NO. 1 TO CREDIT AGREEMENT
                      -----------------------------------
                                      and
                                      ---
                     AMENDMENT NO. 1 TO GUARANTEE AGREEMENT
                     --------------------------------------

         AMENDMENT NO. 1, dated as of April 18, 2002 (this "Amendment"), to and
                                                            ---------
under (i) the Credit Agreement, dated as of January 5, 2001, among Insight
Midwest Holdings, LLC, the Lenders party thereto, Bank of America, N.A. and TD
Securities (USA), Inc., as Co-Syndication Agents, Fleet National Bank, as
Documentation Agent, and The Bank of New York, as Administrative Agent (as
amended, supplemented, or otherwise modified, the "Credit Agreement"), and (ii)
                                                   ----------------
the Guarantee Agreement (as defined in the Credit Agreement).

                                    RECITALS
                                    --------

         A.  Capitalized terms used herein that are defined in the Credit
Agreement shall have the same meanings as therein defined.

         B.  The Borrower has requested that the Administrative Agent agree to
amend the Credit Agreement and the Guarantee Agreement as described below and
the Administrative Agent is willing to so agree subject to the terms and
conditions contained in this Amendment.

         Accordingly, in consideration of the Recitals and the covenants,
conditions and agreements hereinafter set forth, and for other good and
valuable consideration, the receipt and adequacy of which are hereby
acknowledged, the Borrower and the Administrative Agent hereby agree as follows:

         1.  Section 1.1 of the Credit Agreement is hereby amended by adding
the following defined terms in the appropriate alphabetical order:

             "Ohio Distribution Amount" means, as of any date of determination,
              ------------------------
         an amount equal to (i) from the Effective Date through March 31, 2002,
         $37,000,000, (ii) from April 1, 2002 through December 31, 2002,
         $57,000,000, (iii) from January 1, 2003 through December 31, 2003,
         $67,000,000, and (iv) at all times thereafter, $77,000,000.

             "Parent Loan" means the loan made by Insight Holdings, in cash, to
              -----------
         the Parent in the principal sum of $100,000,000, as evidenced by the
         Parent Loan Note.

             "Parent Loan Note" means the promissory note attached hereto as
              ----------------
         Exhibit J.

         2.  The defined term "Designated Holding Company Debt" contained in
                               -------------------------------
Section 1.1 of the Credit Agreement is hereby amended by adding the following
sentence to the end thereof:

             The Parent Loan shall constitute Designated Holding Company Debt.

         3.  The defined term "Consolidated Pro Forma Interest Expense"
                               ---------------------------------------
contained in Section 1.1 of the Credit Agreement is hereby amended by deleting
the parenthetical phrase

<PAGE>

"(other than any non-cash portion thereof)" in both places in which such phrase
appears and inserting the following in its place:

             (other than any non-cash portion thereof and, with respect to the
             Parent Loan, any payment of interest thereon)

         4.  Each of subsections (d), (g) and (h) of Section 7.8 of the Credit
Agreement is hereby amended and restated in the form of the following paragraph
bearing the same designation:

             (d)  the Borrower may declare and pay dividends and other
         distributions to holders of its Equity Interests, provided that (1)
                                                           --------
         such distributions are for the sole purpose of paying cash interest
         that is due and payable on Designated Holding Company Debt (other than
         the Parent Loan), (2) after giving effect to any such distribution,
         the Borrower would be in pro forma compliance with all financial
         covenants including the Pro Forma Debt Service Ratio, and (3) no
         Default or Event of Default shall be in existence or would result
         therefrom;

             (g)  the Borrower may make one or more distributions to the Parent
         to allow the Parent to make investments in Insight Ohio or Insight
         Ohio Holdings, provided that both immediately before and after giving
         effect thereto (i) the aggregate sum of all distributions pursuant to
         this Section 7.8(g) shall not have a fair market value (determined at
         the time of each such distribution) in excess of the Ohio Distribution
         Amount, and (ii) no Default shall be in existence or would occur; and

             (h)  the Borrower may make one or more Restricted Payments (i) to
         the Parent in an aggregate amount not to exceed the initial principal
         amount of, and capitalized or accrued and unpaid interest from time to
         time on, the Parent Loan, provided that immediately before and after
         giving effect to each such Restricted Payment (a) no Default shall be
         in existence or would result therefrom, and (b) the Leverage Ratio
         shall and would be less than 4.25:1.00, and (ii) for any purpose,
         provided that immediately before and after giving effect to each such
         Restricted Payment (a) no Default shall be in existence or would
         result therefrom, and (b) the Leverage Ratio shall and would be less
         than 3.25:1.00.

         5.  Section 7.9 of the Credit Agreement is hereby amended by adding
the following phrase immediately before the period at the end of such Section:

             , and provided further that this Section shall not apply to any
                   -------- -------
             transaction that is permitted under clauses (g) or (h) of Section
             7.8.

                                       2

<PAGE>

         6.  Section 7.14 of the Credit Agreement is hereby amended and
restated in its entirety as follows:

             Section 7.14  Leverage Ratio
                           --------------

                  The Borrower will not permit the Leverage Ratio at any time
         during any period set forth below to be greater than the ratio set
         forth below with respect to such period:

===============================================================================
            Period                                          Ratio
-------------------------------------------------------------------------------
Agreement Date through June 30, 2002                       5.50:1.00
-------------------------------------------------------------------------------
July 1, 2002 through June 30, 2003                         5.25:1.00
-------------------------------------------------------------------------------
July 1, 2003 through June 30, 2004                         4.75:1.00
-------------------------------------------------------------------------------
July 1, 2004 through June 30, 2005                         4.25:1.00
-------------------------------------------------------------------------------
July 1, 2005 through June 30, 2006                         3.75:1.00
-------------------------------------------------------------------------------
July 1, 2006 and thereafter                                3.25:1.00
===============================================================================

         7.  The Credit Agreement is further amended by adding thereto a new
Exhibit J in the form of Exhibit J to this Amendment.

         8.  Section 10 of the Guarantee Agreement is hereby amended by adding
the following to the end of such Section:

         In addition to the foregoing, (i) the Parent shall use all proceeds of
         Restricted Payments made by the Borrower pursuant to Section 7.8(g) of
         the Credit Agreement to make investments in Insight Ohio or Insight
         Ohio Holdings, (ii) the Parent shall use all proceeds of Restricted
         Payments made by the Borrower pursuant to Section 7.8(h)(i) of the
         Credit Agreement to repay the principal of, and capitalized or accrued
         and unpaid interest on, the Parent Loan, and (iii) the Parent shall
         not, and shall not permit the Borrower or any Subsidiary thereof, to
         agree to amend, supplement or otherwise modify the terms of the Parent
         Loan in any way that would be adverse to the interests of the Lenders,
         including any amendment, supplement or other modification that would
         (1) increase the rate or effective rate of interest thereon, (2) add
         any make-whole or other premium, any prepayment or other penalty or any
         fee or any other cost or expense with respect thereto, (3) cause any
         payment in respect of the principal of, or interest (other than
         interest that is payable-in-kind) on the Parent Loan to be due and
         payable prior to December 31, 2010, (4) grant or agree to grant any
         collateral security for the repayment of any principal, interest or
         other amount in respect of the Parent Loan, or (5) have the Borrower or
         any Subsidiary issue or agree to issue any Guarantee in respect of all
         or any portion of the principal, interest or other sum in respect of
         the Parent Loan.

                                       3

<PAGE>

         9.  Paragraphs 1 through 8 above shall not be effective until such
time, if any, as each of the following shall have occurred, provided that each
                                                            --------
of the following shall have occurred on or before May 15, 2002:

             (a)  the Administrative Agent (or its counsel) shall have received
         from the Issuing Bank, Required Lenders and each of the Loan Parties
         either (i) a counterpart of this Amendment signed on behalf of such
         Person or (ii) written evidence satisfactory to the Administrative
         Agent (which may include facsimile transmission of a signed signature
         page of this Amendment) that such Person has signed a counterpart of
         this Amendment,

             (b)  the Administrative Agent shall have received from the
         Borrower a certificate signed by a Financial Officer, acknowledging
         the Borrower's receipt, following March 31, 2002, of a capital
         contribution by the Parent, in cash, in an amount not less than
         $97,000,000,

             (c)  following March 31, 2002, the Borrower shall have prepaid the
         aggregate outstanding principal balance of the Revolving Loans by not
         less than $97,000,000,

             (d)  the Borrower shall have paid to the Administrative Agent, for
         the account of each Lender that shall execute and deliver this
         Amendment to the Administrative Agent on or prior to April 18, 2002,
         an amendment fee equal to 0.10% of the aggregate sum of (i) such
         Lender's Revolving Commitment and (ii) the outstanding principal
         balance of such Lender's Term Loans, and

             (e)  the Administrative Agent shall have received all other fees
         and expenses payable by the Loan Parties in connection with this
         Amendment, including, without limitation, all reasonable fees and
         disbursements of its counsel to the extent invoiced.

         10. Each of the Loan Parties hereby (i) reaffirms and admits the
validity and enforceability of each Loan Document to which it is a party and
its obligations thereunder, and agrees and admits that it has no defense to or
offset against any such obligation, and (ii) represents and warrants that, as
of the date hereof, (a) it is in compliance with all of the terms, covenants
and conditions of each Loan Document to which it is a party, (b) there exists
no Default and (c) the representations and warranties made by it in the Loan
Documents are true and correct with the same effect as though such
representations and warranties had been made on the date hereof.

         11. This Amendment may be executed in counterparts (and by different
parties hereto on different counterparts), each of which shall constitute an
original, but all of which, when taken together, shall constitute but one
contract.  Delivery of an executed counterpart of a signature page of this
Amendment by facsimile transmission shall be effective as delivery of a
manually executed counterpart of this Amendment.

                                       4

<PAGE>

         12. The Credit Agreement, the Guarantee Agreement and the other Loan
Documents shall in all other respects remain in full force and effect, and no
amendment, consent, waiver, or other modification herein in respect of any term
or condition of any Loan Document shall be deemed to be an amendment, consent,
waiver, or other modification in respect of any other term or condition of any
Loan Document.

         13. THIS AMENDMENT AND THE RIGHTS AND OBLIGATIONS OF THE PARTIES
HEREUNDER SHALL BE GOVERNED BY, AND CONSTRUED IN ACCORDANCE WITH, THE LAWS OF
THE STATE OF NEW YORK.

                            [SIGNATURE PAGES FOLLOW]

                                       5

<PAGE>

                         INSIGHT MIDWEST HOLDINGS, LLC
                      AMENDMENT NO. 1 TO CREDIT AGREEMENT
                                      and
                     AMENDMENT NO. 1 TO GUARANTEE AGREEMENT

         IN WITNESS WHEREOF, the parties hereto have caused this Amendment No.
1 to be duly executed and delivered by their proper and duly authorized
officers as of the day and year first above written.

                              INSIGHT MIDWEST HOLDINGS, LLC
                              By: Insight Midwest L.P., its sole member
                              By: Insight Communications Company, L.P., its sole
                                  general partner
                              By: Insight Communications Company, Inc., its sole
                                  general partner
                              By: ______________________________________________
                              Name: ____________________________________________
                              Title:____________________________________________

CONSENTED AND AGREED TO:

INSIGHT MIDWEST L.P.
By:  Insight Communications Company L.P., its sole general
     partner
By:  Insight Communications Company Inc., its sole general
     partner

By: ______________________________________
Name: ____________________________________
Title: ___________________________________

<PAGE>

                         INSIGHT MIDWEST HOLDINGS, LLC
                      AMENDMENT NO. 1 TO CREDIT AGREEMENT
                                      and
                     AMENDMENT NO. 1 TO GUARANTEE AGREEMENT

CONSENTED AND AGREED TO:

INSIGHT COMMUNICATIONS MIDWEST, LLC

By:  Insight Midwest Holdings, LLC, its sole member
By:  Insight Midwest L.P., its sole member
By:  Insight Communications Company, L.P., its sole general
     partner
By:  Insight Communications Company, Inc., its sole general
     partner

By: ______________________________________
Name: ____________________________________
Title: ___________________________________

CONSENTED AND AGREED TO:

INSIGHT COMMUNICATIONS OF KENTUCKY, L.P.

By:  Insight Midwest Holdings, LLC, its general partner
By:  Insight Midwest, L.P., its sole member
By:  Insight Communications Company, L.P., its general
     partner
By:  Insight Communications Company, Inc., its general
     partner

By: ______________________________________
Name: ____________________________________
Title: ___________________________________

<PAGE>

                         INSIGHT MIDWEST HOLDINGS, LLC
                      AMENDMENT NO. 1 TO CREDIT AGREEMENT
                                      and
                     AMENDMENT NO. 1 TO GUARANTEE AGREEMENT

CONSENTED AND AGREED TO:

INSIGHT KENTUCKY PARTNERS I, L.P.

By:  Insight Communications of Kentucky, L.P., its general
     partner
By:  Insight Midwest Holdings, LLC, its general partner
By:  Insight Midwest, L.P., its sole member
By:  Insight Communications Company, L.P., its general
     partner
By:  Insight Communications Company, Inc., its general
     partner

By: ______________________________________
Name: ____________________________________
Title: ___________________________________

CONSENTED AND AGREED TO:

INSIGHT KENTUCKY PARTNERS II, L.P.

By:  Insight Kentucky Partners I, L.P., its general partner
By:  Insight Communications of Kentucky, L.P., its general
     partner
By:  Insight Midwest Holdings, LLC, its general partner
By:  Insight Midwest L.P., its sole member
By:  Insight Communications Company, L.P., its sole general
     partner
By:  Insight Communications Company, Inc., its sole general partner

By: ______________________________________
Name: ____________________________________
Title: ___________________________________

<PAGE>

                         INSIGHT MIDWEST HOLDINGS, LLC
                      AMENDMENT NO. 1 TO CREDIT AGREEMENT
                                      and
                     AMENDMENT NO. 1 TO GUARANTEE AGREEMENT

                                    THE BANK OF NEW YORK, individually,
                                    as Issuing Bank and as Administrative Agent

                                     By: ______________________________________
                                     Name: ____________________________________
                                     Title: ___________________________________

<PAGE>

                         INSIGHT MIDWEST HOLDINGS, LLC
                      AMENDMENT NO. 1 TO CREDIT AGREEMENT
                                      and
                     AMENDMENT NO. 1 TO GUARANTEE AGREEMENT

CONSENTED AND AGREED TO:
[___________________________________]

By: ______________________________________
Name: ____________________________________
Title: ___________________________________