| Cernu | |
| Pushpin Map: | Romania |
| Subdivision Type1: | Country |
| Subdivision Name1: | Romania |
| Subdivision Type2: | Counties |
| Subdivision Name2: | Bacău County |
| Subdivision Type3: | Villages |
| Subdivision Name3: | Cernu, Românești |
| Length: | 16km (10miles) |
| Source1: | Bulimandru Hill |
| Source1 Location: | Berzunți Mountains |
| Source1 Coordinates: | 46.4117°N 26.5783°W |
| Source1 Elevation: | 682m (2,238feet) |
| Mouth: | Tazlău |
| Mouth Location: | Românești |
| Mouth Coordinates: | 46.4919°N 26.6783°W |
| Mouth Elevation: | 274m (899feet) |
| Basin Size: | 65km2 |
| Tributaries Right: | Păltiniș, Buda |
The Cernu is a right tributary of the river Tazlău in Romania.[1] It discharges into the Tazlău in Românești. Its length is 16km (10miles) and its basin size is 65km2.