<PAGE>   1
                      SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C. 20549

   
                                 FORM 10-Q/A
                               AMENDMENT NO. 1
    

(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, 1997

                                       or

/  /     Transition report pursuant to Section 13 or 15(d) of the Securities 
         Exchange Act of 1934

         For the transition period from __________ to __________

                          Commission File No. 0-17909

                             PHOENIX NETWORK, INC. 
             ------------------------------------------------------
             (Exact Name of Registrant as Specified in Its Charter)
 
            Delaware                                  84-0881154 
-------------------------------            ---------------------------------
(State or Other Jurisdiction of            (IRS Employer Identification No.)
Incorporation or Organization)

                   1687 Cole Boulevard, Golden, Colorado 80401
               --------------------------------------------------
               (Address of principal executive offices)(Zip Code)

Registrant's telephone number, including area code: (303) 205-3500

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.

                           (1) Yes   X    (2) No 
                                   ----          -----
Indicate the number of shares outstanding of each of the issuer's classes of
common stock, as of the latest practicable date.

                                           Shares outstanding at
           Class                               May 1, 1997
 -----------------------------             ---------------------
 Common Stock, $.001 par value                  25,924,745
<PAGE>   2
   
                        PART I. FINANCIAL INFORMATION
    


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

Results of Operations

For the quarter ended March 31, 1997 revenues decreased to $21,357,696 compared
with revenues of $27,336,312 for the comparable period of the prior year. The
decrease was primarily due to a 14.2% decrease in the average revenue per
minute. The average rate decline was due to the Company's customers utilizing
more competitively priced services offered by the Company over the past year as
a result of the Company's reaction to an overall decline in retail rates and
price sensitivity in the telecommunications industry.

Cost of revenues for the three months ended March 31, 1997 decreased to
$15,431,689 from $19,818,948 in the prior year's period which, as a percentage
of revenue decreased slightly to 72.2% compared to 72.5% for the prior year's
period.  Accordingly, the gross profit increased to 27.7% for the first quarter
'97 as compared to 27.5% for first quarter '96.  The Company recently announced
that it had entered into a letter of intent to merge with US ONE Communications
Corp., a Dallas, Texas based CLEC (competitive local exchange carrier) which
owns and operates a national network of Lucent 5ESS- 2000 switches capable of
both local dialtone and long distance telephone services. US ONE has designed
and deployed what is considered to be one of the most advanced
telecommunications infrastructures in the country, with switches located in New
York City, Chicago, Los Angeles, Boston, Washington D.C., Atlanta, Tampa,
Columbus, Minneapolis, Kansas City, Dallas, Denver, San Francisco, and Seattle.
Five of such switches are currently handling call traffic, and, to date the
Company has successfully converted more than 15% of its traffic to the US ONE
network.

Selling, general and administrative (SG&A) expenses decreased from $7,819,696
for the first quarter of '96 to $7,069,572 for the first quarter of '97. The
Company has realized cost savings due to the completion of the consolidation of
its San Francisco operations into the former ACI facilities in Golden, Colorado
during the first half of 1996. However, as a percentage of revenue, SG&A costs
have increased by 4.5% between first quarter '96 and first quarter '97.

Depreciation and amortization expense decreased from $1,104,178 in the March 96
quarter to $978,966 in the quarter ended March 1997. The decrease resulted
primarily from the write-down of prepaid telemarketing commissions at year end.




   
    

                                      2
<PAGE>   3
Liquidity and Capital Resources

   
Net cash used in operating activities for the quarter ended March 1997 was
$2,530,328 compared to $1,392,480 for the quarter ended March 1996, primarily
as a result of the loss incurred for the period. The Company believes that the
proposed merger with US ONE Communications will result in increasingly lower
line costs over the next year as the Company is able to transition more of its
traffic onto the US ONE network. The Company has a line of credit available
through a finance company allowing for borrowings of up to $10,000,000 based on
the Company's trade receivables. There was $7,311,970 outstanding under the
line at March 31, 1997. As of March 31, 1997 the Company had $692,080 of
borrowings that were available under the $10 million line of credit.
    

   
It was the Company's policy to maintain account receivables balances on its
general ledger despite their age for up to one year. Amounts deemed
uncollectible are fully reserved within the allowance for doubtful accounts.
The increase in allowance for doubtful accounts during the first quarter of
1997 is based on the Company's estimate of uncollectible balances relating to
first quarter sales. Effective as of the second quarter of 1997, the Company
has revised this policy to write-off uncollectible accounts after 90 days.
    




                                       3
<PAGE>   4
                                   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.


                                           PHOENIX NETWORK, INC.
                                           ---------------------
                                           (Registrant)


   
Date 6/17/97                               /s/ Wallace M. Hammond 
     ------------                          --------------------------------
    
                                           Wallace M. Hammond
                                           Chief Executive Officer



   
Date 6/17/97                               /s/ Jon Beizer 
     ------------                          --------------------------------
    
                                           Jon Beizer
                                           Chief Financial Officer
                                           (Chief Accounting Officer)





                                       4