Erstfeld is first mentioned in 1258 as Ourzcvelt. In 1638 it was listed under the Latin name in Protocampis. In 1831 it was known as Hirschfelden.
Erstfeld has an area, , of . Of this area, 11.7% is used for agricultural purposes, while 29.2% is forested. Of the rest of the land, 2.8% is settled (buildings or roads) and the remainder (56.2%) is non-productive (rivers, glaciers or mountains).
The municipality consists of the linear village of Erstfeld and scattered farm houses along the valley floor and up the mountain sides.
Erstfeld is at the base of the northern ramp of the Gotthard railway and houses all the rolling stock needed for the rail line.