west by the Pacific Ocean, to the east by the Republic of Argentina, to the north by the Valparaíso and Santiago Metropolitan Regions, and to the south by the Maule Region. It extends approximately between the parallels of 33° 51' and 35° 01' south latitude, and between the meridian of 70° 02' west longitude and the Pacific Ocean.

The capital and largest city of the region is Rancagua.