The canton Gascogne-Auscitaine has 22 communes.
| Code | Name | Population ▼ |
|---|---|---|
| 32331 | Preignan | 1 202 |
| 32162 | Jegun | 1 176 |
| 32117 | Duran | 862 |
| 32301 | Ordan-Larroque | 858 |
| 32279 | Montaut-les-Créneaux | 697 |
| 32348 | Roquelaure | 563 |
| 32368 | Sainte-Christie | 541 |
| 32335 | Puycasquier | 420 |
| 32054 | Biran | 379 |
| 32204 | Lavardens | 363 |
| 32091 | Castin | 337 |
| 32347 | Roquefort | 275 |
| 32384 | Saint-Lary | 271 |
| 32112 | Crastes | 264 |
| 32258 | Mirepoix | 227 |
| 32089 | Castillon-Massas | 222 |
| 32014 | Augnax | 132 |
| 32316 | Peyrusse-Massas | 117 |
| 32059 | Bonas | 106 |
| 32453 | Tourrenquets | 99 |
| 32251 | Mérens | 66 |
| 32003 | Antras | 40 |