<ARTICLE> 5
<CIK> 0000931755
<NAME> AEI INCOME & GROWTH FUND XXI LIMITED PARTNERSHIP
       
                             
<PERIOD-TYPE>                   3-MOS
<FISCAL-YEAR-END>                          DEC-31-1999
<PERIOD-END>                               MAR-31-1999
<CASH>                                         296,601
<SECURITIES>                                         0
<RECEIVABLES>                                        0
<ALLOWANCES>                                         0
<INVENTORY>                                          0
<CURRENT-ASSETS>                               296,601
<PP&E>                                      18,793,585
<DEPRECIATION>                               (946,306)
<TOTAL-ASSETS>                              18,143,880
<CURRENT-LIABILITIES>                          471,550
<BONDS>                                              0
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                             0
<OTHER-SE>                                  17,672,330
<TOTAL-LIABILITY-AND-EQUITY>                18,143,880
<SALES>                                              0
<TOTAL-REVENUES>                               485,350
<CGS>                                                0
<TOTAL-COSTS>                                  212,078
<OTHER-EXPENSES>                                     0
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                                   0
<INCOME-PRETAX>                                273,272
<INCOME-TAX>                                         0
<INCOME-CONTINUING>                            273,272
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                   273,272
<EPS-PRIMARY>                                    11.35
<EPS-DILUTED>                                    11.35