This river should not be confused with the Pissa river in Russia, nor with the smaller Pisa river.

The Pisa (Pissek) is a small river with a length of 80.4 km in the Masurian Lake District of the Warmian-Masurian Voivodeship of Poland. The Pisa flows from Lake Roś near Pisz and is a tributary of the Narew, connecting the lakeland region with the Vistula. The Piska Forest borders the river on its west bank.

The river's name, like Pisz, comes from the Old Prussian word pisa, or swamp. Because the Prussian Galindae tribe once lived in the area, the Teutonic Knights referred to the Pisa as the Galinde.