| Lengyendi | |
| Source1 Elevation: | 870m (2,850feet) |
| Mouth Coordinates: | 47.9954°N 19.8654°W |
| Subdivision Type1: | Country |
The Lengyendi originates in Mátra, above sea level, Northwest from Galyatető, Nógrád County, Hungary. It flows to North up to Nemti, where it flows into the Zagyva.