Sheets of Mongolia, 1978
| Issuer | Date | Desc | State | ||
| - |  |
Mongolia | 3/25/1978 | 75th Anniversary of Powered Flight, empty sheet (#16816) | incomplete |
| - |  |
Mongolia | 4/15/1978 | World Cup 1978, empty sheet (#16817) | incomplete |
| - |  |
Mongolia | 5/29/1978 | CAPEX '78, sheet of 1 type | all added |
| - |  |
Mongolia | 8/10/1978 | 20th Anniversary of Philatelic Co-operation between Mongolia and Hungary, sheet of 3 types | incomplete |
| - |  |
Mongolia | 9/5/1978 | PRAGA '78, sheet of 1 type | all added |
| - |  |
Mongolia | 10/20/1978 | empty sheet (#16821) | incomplete |
| - |  |
Mongolia | 10/20/1978 | empty sheet (#16822) | incomplete |