| Place | Post Code |
|---|---|
| Bolków, Ostrówek | 98-311 |
| Dębiec, Ostrówek | 98-311 |
| Dymek, Ostrówek | 98-311 |
| Gwizdałki, Ostrówek | 98-311 |
| Jackowskie, Ostrówek | 98-311 |
| Janów, Ostrówek | 98-311 |
| Kopiec, Ostrówek | 98-311 |
| Koźlin, Ostrówek | 98-311 |
| Kuźnica, Ostrówek | 98-311 |
| Milejów, Ostrówek | 98-311 |
| Niemierzyn, Ostrówek | 98-311 |
| Nietuszyna, Ostrówek | 98-311 |
| Okalew, Ostrówek | 98-311 |
| Oleśnica, Ostrówek | 98-311 |
| Ostrówek, Ostrówek | 98-311 |
| Piskornik, Ostrówek | 98-311 |
| Rudlice, Ostrówek | 98-311 |
| Skrzynno, Ostrówek | 98-311 |
| Ugoda-Niemierzyn, Ostrówek | 98-311 |
| Wielgie, Ostrówek | 98-311 |
| Wola Rudlicka, Ostrówek | 98-311 |