Trichogenes longipinnis, a new genus and species, is described from small litoranean rivers of Southeastern Brazil. The new genus was included in the Trichomycterinae, but when compared with two other genera of the subfamily (Trichomycterus and Hatcheria) revealed significant differences. Trichogenes can be characterized as follows: (1) opercle with two patches of spines; spines present on the interopercle also; (2) nasal barbel present; two barbels at the angle of the mouth; no mental barbels; (3) orbit with a free margin; (4) gill-membranes free from the isthmus; (5) first ray of the pectoral fin not pungent; (6) dorsal fin short (9 rays), nearer the caudal fin base than the tip of the snout; (7) origin of the ventral in front of the middle of the body; (8) anal long (more than 30 rays), its origin before the dorsal fin base; (9) infraorbital canal complete, formed by the lacrimal plus 6 tube-shaped infraorbitals and (11) gas-bladder capsule separated from the posterior part of the skull.