The lesser long-nosed bat is gray or yellow-brown above and reddish-brown below, with a short tail and small ears. It has a triangular shaped nose leaf, a projection of skin above the nostrils, which juts from the end of its nose. This species of bat is medium-sized and weighs less than 25 grams. It is 2.5 to 3 inches long and has a 14 inch wingspan. Juvenile lesser long-nosed bats have gray fur.

These bats eat nectar, pollen, and fruit and feed exclusively on night-blooming cacti, with columnar cactus flowers and fruits and agave flowers representing its core diet.

This species is found in southern Arizona and southwestern New Mexico south to western Mexico and Baja California del Sur. In 1988 these bats were listed as endangered under the Endangered Species Act.