<TABLE> <S> <C>

<PAGE>
 
<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE BALANCE
SHEET AND INCOME STATEMENT OF OMNIPOINT CORPORATION AS OF AND FOR THE NINE
MONTHS ENDED SEPTEMBER 30, 1998, FOR THE TWELVE MONTHS ENDED DECEMBER 31, 1998
AND FOR THE SIX MONTHS ENDED JUNE 30, 1998 AND IS QUALIFIED IN ITS ENTIRETY BY
REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000
       
<S>                             <C>                     <C>                    
<PERIOD-TYPE>                   9-MOS                   YEAR              
<FISCAL-YEAR-END>                          DEC-31-1998             DEC-31-1998       
<PERIOD-START>                             JAN-01-1998             JAN-01-1998       
<PERIOD-END>                               SEP-30-1998             DEC-31-1998       
<CASH>                                         194,732                 148,309       
<SECURITIES>                                    43,571                     267       
<RECEIVABLES>                                   51,500                  47,001       
<ALLOWANCES>                                    13,435                  11,826       
<INVENTORY>                                     29,729                  34,652       
<CURRENT-ASSETS>                               328,154                 239,576       
<PP&E>                                       1,181,532               1,078,779      
<DEPRECIATION>                                (150,357)               (117,003)      
<TOTAL-ASSETS>                               2,066,604               1,931,521       
<CURRENT-LIABILITIES>                          369,454                 337,437       
<BONDS>                                      6,013,896                 478,689       
<PREFERRED-MANDATORY>                                0                       0       
<PREFERRED>                                    276,191                 270,462       
<COMMON>                                           531                     528       
<OTHER-SE>                                    (586,551)               (387,749)      
<TOTAL-LIABILITY-AND-EQUITY>                 2,066,604               1,931,521       
<SALES>                                        167,752                 195,161       
<TOTAL-REVENUES>                               172,536                 118,412       
<CGS>                                          228,419                 160,216       
<TOTAL-COSTS>                                  228,419                 160,216       
<OTHER-EXPENSES>                               400,924                 273,048       
<LOSS-PROVISION>                                     0                       0       
<INTEREST-EXPENSE>                             187,187                 136,660       
<INCOME-PRETAX>                               (657,667)               (451,052)       
<INCOME-TAX>                                         0                       0       
<INCOME-CONTINUING>                           (657,667)               (451,052)       
<DISCONTINUED>                                       0                       0       
<EXTRAORDINARY>                                (11,115)                (11,115)      
<CHANGES>                                            0                       0       
<NET-INCOME>                                  (663,782)               (470,883)      
<EPS-PRIMARY>                                   (12.87)                  (8.96)       
<EPS-DILUTED>                                   (12.87)                  (8.96)       
        

</TABLE>