Pimelodus carcio, originally described in 1822 by Francis Hamilton, has long been treated as a junior synonym of either Mystus tengara or M. vittatus. In this paper we revalidate and redescribe the species and diagnose it from other striped Mystus by the following combination of characters: small adult size, maturing at 44.0 mm standard length; adipose-fin base shorter than or equal to dorsal-fin base; pelvic fin reaching anal-fin origin; pectoral girdle with coracoid shield exposed ventro-laterally below pectoral fin; eyes rounded and large, dorsally orientated on head; vomerine tooth-patch interrupted at midline. The species is distributed in the Ganga-Brahmaputra drainage of northeast India and Bangladesh.