Sheets of Palau, 1991
| Issuer | Date | Desc | State | ||
| - | no image | Palau | 3/14/1991 | Angaur, The Phosphate Island, sheet of 16 types | |
| - | no image | Palau | 4/28/1991 | 100th Anniversary of Christianity in Palau Islands, empty sheet (#35930) | incomplete |
| - |  |
Palau | 5/24/1991 | empty sheet (#13229) | incomplete |
| - | no image | Palau | 7/2/1991 | empty sheet (#35931) | incomplete |
| - | no image | Palau | 7/2/1991 | empty sheet (#35932) | incomplete |
| - | no image | Palau | 7/9/1991 | 10th Anniversary of Republic of Palau, sheet of 8 types | |
| - | no image | Palau | 9/17/1991 | Conservation and Cultivation of Giant Clams, sheet of 4 types | |
| - | no image | Palau | 11/6/1991 | 25th Anniversary of Presence of United States Peace Corps in Palau, sheet of 6 types | |
| - |  |
Palau | 11/19/1991 | PHILANIPPON '91, sheet of 6 types | |
| - | no image | Palau | 11/19/1991 | PHILANIPPON '91, empty sheet (#35937) | incomplete |
| - | no image | Palau | 12/6/1991 | Pacific Theatre in Second World War, sheet of 10 types | all added |