The river is one of the longest tributaries of Struma river – 53 km. It is formed by the rivers Golenska, Bashmandra, Demirkapiiska, which are flowing consistently one after another in Pirinska Bistritsa. The upper and the middle flow passing through the village of Pirin are tumultous. Along the river there’s a road from the village of Pirin to Pirin hut. Pirinska Bistritsa is used for irrigation and hydroelectric power. High water is through March-May and low water through August-September.