Trichaptus Pascoe is a genus of broad-nosed weevils (Curculionidae: Entiminae: Naupactini) endemic to Brazil with a single species, T. mutillarius (Perty), that resembles wasps of the family Mutillidae (Hymenoptera), particularly those of the tropical genera Traumatomutilla André and Hoplomutilla Ashmead. Based on morphological characters of the antennae, eyes, mouthparts, legs, and female and male genitalia, Trichaptus is closely related to Briarius [Fischer de Waldheim] (syn. of Lamprocyphus Marshall). The purpose of this contribution is to redescribe Trichaptus, to diagnose its only known species, and to illustrate its diagnostic features, including genitalia and mouthparts. This information is necessary to undertake a phylogenetic analysis of the whole Naupactini tribe, our main research goal.