Mahendragarh is located at the southern pert of Haryana and lies between 27° 47' and 28° 26' north latitudes and between 75° 56' and 76° 51' east longitudes. Having its headquarters at Narnaul, the district has a total area of 1899 square kilometers and a population of 813 thousands per square kilometers.

Agriculture is the main occupation of the district. Rice, wheat and barley are the main crops cultivated here.

Mahendragarh is the home for many historic and religious sites. Few of the main tourist attractions are Jal Mahal, Chor Gumbad and Birbal ka chatta.
Regions covered by Narnaul and Mahendragarh tehsils from Patiala State, Dadri from Jind State and a section of Bawal nizamat from Nabha State, which were the former princely states, were amalgamated to create the district of Mahendragarh. A section of Patiala and East Punjab States Union State was formed by this district. The Patiala and East Punjab States Union was combined with Punjab on 1st November, 1965. Along with this union, it became an element of Punjab State. Again in 1966, when the Haryana state was created, it was acceded into Haryana. In 1972, the Mahendragarh District was given an addition of the Rewari Tehsil of Gurgaon District. However, again in 1989, the status of a distinct district was given to Rewari Tehsil.