Sheets of Vietnam, 1991
| Issuer | Date | Desc | State | ||
| - |  |
Vietnam | 1/31/1991 | Olympics 1992 in 1991, sheet of 1 type | all added |
| - |  |
Vietnam | 2/22/1991 | 500th Anniversary of Discovery of America, sheet of 1 type | all added |
| - |  |
Vietnam | 5/10/1991 | sheet of 1 type | all added |
| - |  |
Vietnam | 5/24/1991 | sheet of 1 type | all added |
| - |  |
Vietnam | 7/15/1991 | Winter Olympics 1992 in 1991, sheet of 1 type | all added |
| - |  |
Vietnam | 7/26/1991 | sheet of 6 types | all added |
| - |  |
Vietnam | 7/26/1991 | sheet of 6 types | |
| - |  |
Vietnam | 8/20/1991 | sheet of 1 type | all added |
| - |  |
Vietnam | 8/20/1991 | empty sheet (#16133) | incomplete |
| - | no image | Vietnam | 8/20/1991 | empty sheet (#63668) | incomplete |
| - |  |
Vietnam | 8/29/1991 | Philanippon '91, sheet of 1 type | all added |
| - | no image | Vietnam | 9/17/1991 | empty sheet (#63669) | incomplete |