The Luni River basin is 37,363 km², which includes all or part of Ajmer, Barmer, Jalor, Jodhpur, Nagaur, Pali, and Sirohi districts of Rajasthan;≥Mithavirana, Jordiyali, Mavsari Vav, Radhanpur region of Banaskantha North Gujarat.
The district was carved out by amalgamating Sami, Harij, Chanasma, Sidhpur and Patan Talukas of the erstwhile Mehsana District with Radhanpur and Santalpur Talukas of the erstwhile Banaskantha District.