| Piusa | |
| Source1 Location: | Plaani Külajärv |
| Mouth: | Lake Peipus (Pihkva) |
| Subdivision Type1: | Countries |
| Length: | 109km (68miles) |
| Source1 Elevation: | 244m (801feet) |
| Mouth Elevation: | 30m (100feet) |
| Discharge1 Avg: | 5.5- |
| Basin Size: | 796km2 |
| Tributaries Right: | Pelska |
The Piusa (Russian: Пиуза Piuza or Russian: Пимжа Pimzha) is a river in southeastern Estonia and, for the last 14 km before draining into Lake Pihkva, in Pskov Oblast, Russia. For a 17 km section near Pechory, the Piusa is the border river between Estonia and Russia.[1]
The Piusa has the greatest drop of all Estonian rivers (214 metres).[2]