Meristogenys penrissenensis was first described from Mount Penrissen, Kuching Division, Sarawak, at 460 m a.s.l. At the same area it was recorded up to 870 m a.s.l. It is also known from Taman Rekreasi Ranchan Serian and the Matang Range (both Sarawak). Although distribution data are limited, the species is assumed to be widespread in western Borneo, including parts of Kalimantan (Indonesia).

It inhabits rocky streams in lowland forests of Sarawak. Snout–vent length is about 39 mm in males and 70–73 mm in females.

The toes are fully webbed to the tips. Similar to other Meristogenys species the head is narrow and triangular in dorsal view, the snout is protruding in profile, the legs—and the tibia (shank) in particular—are very long relative to snout–vent length, and the toe and finger tips are expanded to form adhesive disks. In M. penrissenensis, the eardrum is half the eye diameter or less in both sexes. 

This species is generally brown in color. The upper side of thigh and tibia is broadly barred. The posterior surface of the thigh is dark brown, mottled with irregular light spots. The tibia (shank) lacks heavy ventral pigmentation. The upper lip bears no distinct markings, while the lower lip is barred, indistinct in males. Meristogenys penrissenensis differs from the sympatric and sometimes syntopic M. jerboa by the absence of the black marking that in M. jerboa extends around the eye, temporal region, tympanum, and anterior flank. In addition, the eye of M. penrissenensis is reddish only in the anterior and posterior sectors of the iris, whereas in M. jerboa the lower part of the iris is entirely reddish. The eardrum is often purplish brown with lighter center. 

Larvae of M. penrissenensis have divided jaw sheaths on the lower jaw, combined with three undivided and four divided keratodont rows on the upper lip (in M. jerboa tadpoles, there are three undivided and three divided rows).