The Nežárka river is the biggest tributary of the Lužnice river, which takes water of the Nežárka river in the town Veselí nad Lužnicí from the right side.
The place where two small rivers - Kamenice and Žirovnice join, near the small town Jarošov nad Nežárkou north-east of the town Jindřichův Hradec - is the beginning of the Nežárka river. The river runs to Jindřichův Hradec and then it continues through the wide valley in the south-western direction to the small town Stráž nad Nežárkou and it turns to the north-west. The Nová Řeka canal (New River), which was built for the regulation of the Lužnice river, flows into Nežárka from the left side near the yard Jemčina. Then the Nežárka river heads to the confluence with the Lužnice river to Veselí nad Lužnicí.
The Nežárka river is a typical lowland river with slow flow with many weirs. It is a favourite place for recreation and swimming and for canoeing - it is navigable on the middle and lower reaches.
The length of the river is 56 km and its river basin is 1,007 square km large.
The part of the river between Jindřichův Hradec and Stráž nad Nežárkou is accessible along the yellow marked tourist trail. The path in the part between Stráž nad Nežárkou and Jemčina is marked by the red sign and in the section between Jemčina and the settlement Hamr by the green sign. The blue marked trail runs along the remaining part to the confluence with the Lužnice river in Veselí nad Lužnicí.