Exhibit 11.1

ALLEGIANCE TELECOM, INC.        COMPUTATION OF PER SHARE LOSS        THREE MONTHS ENDED SEPTEMBER 30, 2002

|                                      |                                                     | Number of Shares |            | Percent Outstanding |        | Equivalent Shares |             
|------------------------------------- | --------------------------------------------------- | ---------------- | ---------- | ------------------- | ------ | ----------------- | ------------
|Prior to Initial Public Offering      |                                                     |                  |            |                     |        |                   |             
|                                      | 1997 Common Stock Offering                          |                  | 639        |                     | 100.00 | %                 |             
|After Initial Public Offering         |                                                     |                  |            |                     |        |                   |             
|                                      | 1998 Common Stock Offering                          |                  | 15,000,000 |                     | 100.00 | %                 |             
|                                      | Preferred Stock Converted to Common Stock           |                  | 60,511,692 |                     | 100.00 | %                 |             
|                                      | 1999 Common Stock Offering                          |                  | 21,041,100 |                     | 100.00 | %                 |             
|                                      | 2000 Common Stock Offering                          |                  | 10,703,109 |                     | 100.00 | %                 |             
|                                      | Cash in Lieu of Stock Split                         |                  | (577       | )                   | 100.00 | %                 |             
|                                      | Treasury Shares                                     |                  | (327,495   | )                   | 100.00 | %                 |             
|                                      | Warrants Exercised                                  |                  | 768,021    |                     | 99.84  | %                 |             
|                                      | Stock Options Exercised                             |                  | 1,362,257  |                     | 100.00 | %                 |             
|                                      | Employee Stock Discount Purchase Plan Shares Issued |                  | 2,319,736  |                     | 99.48  | %                 |             
|                                      | Common Stock Issued for Business Acquisitions       |                  | 5,558,747  |                     | 100.00 | %                 |             
|                                      | Restricted Shares Issued to Employees               |                  | 1,226,768  |                     | 22.29  | %                 |             
|                                      |                                                     |                  |            |                     |        |                   |             
|WEIGHTED AVERAGE SHARES OUTSTANDING   |                                                     |                  |            |                     |        |                   | 117,197,411 
|NET LOSS APPLICABLE TO COMMON STOCK   |                                                     |                  |            |                     |        | $                 | (113,110,000
|                                      |                                                     |                  |            |                     |        |                   |             
|NET LOSS PER SHARE, BASIC AND DILUTED |                                                     |                  |            |                     |        | $                 | (0.97       
|                                      |                                                     |                  |            |                     |        |                   |             

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