Unterschächen is a municipality in the canton of Uri in Switzerland, situated in the upper Schächental.

Of the rest of the land, 0.8% is settled (buildings or roads) and the remainder (54.2%) is non-productive (rivers, glaciers or mountains).

Most of the population (as of 2000[update]) speaks German (99.6%), with Italian being second most common ( 0.3%) and Portuguese being third ( 0.1%).

The wettest month is August during which time Unterschächen receives an average of 196 mm (7.7 in) of precipitation.

The driest month of the year is October with an average of 107 mm (4.2 in) of precipitation over 14.8 days.