The species was originally described by Inger (1966) from Nanga Tekalit, Mengiong River, Third Division, Sarawak. Specimens shown on this page were collected from Tawau Hills (Sabah) and Batang Ai (Sarawak). Kalophrynus intermedius is a ground-dwelling, stocky frog found in lowland rainforest. Females reach up to 40 mm in snout–vent length (SVL), while males remain smaller.

A light-colored diagonal dorsolateral stripe on the trunk, as seen in some other Kalophrynus species, is absent. The subarticular tubercles beneath the fingers are present, with the fourth finger being nub-like. The toes are about two-thirds webbed, with small, indistinct inner and outer metatarsal tubercles.

The face, chest, and sometimes the flanks are orange-brown. The throat bears two longitudinal bands. An elongate gland above and behind the ear dissolves into a series of warts, separating the dorsum from the flank down to the groin. The dorsum is brown with some faint darker markings, while the flank is lighter in color.

The abundance of this species has not been studied. It may be locally common, but it is rarely encountered in the forest. Like other sticky frogs, this species prefers walking to hopping. When molested, sticky frogs secrete a sticky white substance from their skin (advice: avoid getting the substance on your hands).