| Piyain River | |
|---|---|
.jpg) | |
 | |
| Location | |
| Countries | India, Bangladesh |
| District | Sylhet |
| Physical characteristics | |
| Source | |
| • location | Umgat river of Assam |
| Mouth | |
• location | Surma River |
| Length | 145 kilometres (90 mi) |
Piyain River a trans-boundary river of India and Bangladesh.[1] It is a tributary of the Surma river, which is originates from the Umngot of Meghalaya. The river enters Bangladesh through Sylhet district.