The Luni River flows in the western part of India in the state of Rajasthan. The Luni River is also referred as the Lavanavari River, which means `salt river` in Sanskrit. It rises in the Pushkar valley of the Aravalli Range at an elevation of five hundred fifty metres near Ajmer.

The river then flows in the southwest direction through the hills and plains of the Marwar region in Rajasthan. It finally ends up in the marshy land of Rann of Kutch. The river and its tributaries flow through the western slopes of the Aravalli Range. The river has a total catchment area of 37,363 square kilometers. It covers parts of Ajmer, Pali, Jodhpur, Nagaur, Barmer, Jalore and Sirohi districts and Mithavirana Vav Radhanpur region of Banaskantha North Gujarat. The major tributaries of the Luni River are Sukri, Mithri, Bandi, Khari, Jawai, Guhiya and Sagi from the left bank, and the Jojari River from the right bank.

In the western part of the Aravalli hills where it rises it is called Sagarmati and travels for five hundred and thirty kilometers. The river is highly saline but serves as the primary source of irrigation in the region.