The pecan grows best on rich, moist soils of well-drained river bottomlands. It usually occurs as an occasional tree in association with sweetgum, American elm, common persimmon, honeylocust, hackberry, poplars, and water oak. 

It grows mainly in the southern Mississippi valley: from southwestern Indiana to southeastern Iowa, south through western Tennessee to northern Florida, and south and west through southern Kansas to east central Texas. It also grows in the mountains of Mexico.