The adults and larvae of a new species of Rana are described from representative mountain ranges of the Malay Peninsula, namely Hala Bala Wildlife Sanctuary (south Thailand), Maxwell's Hill, Cameron Highlands, Fraser's Hill and Genting Highlands, with Cameron Highlands designated as the type locality. Both adults and larvae of this montane form have been previously misidentified as either of two Rana species (R. signata or R. glandulosa). Adults of this new highland species may be diagnosed by a combination of the following characters: (a) presence of dorsolateral skin folds in varying degrees, (b) longitudinal dermal ridges on tibia, (c) reduced webbing on hindfeet, (d) raised granules on dorsum and flanks, each granule tipped with whitish asperities and surrounded by smaller ones [in both sexes], (e) similar asperities on dorsal surfaces of fore- and hindlimbs [in both sexes], (f) presence of nuptial pad on first finger, subgular vocal sacs, but absence of humeral gland [in males]. The diagnostic characters of its tadpoles include: (a) a large size [maximum attainable total length ca. 65 mm], (b) presence of sub-dermal whitish glandules on body and tail fins, (c) black spots on body and tail, (d) oral disc not emarginate, (c) labial tooth row formula of 3(2-3)/3(l) with short third row on posterior labium.
