The long-horned caddisfly genus Triplectides Kolenati, 1859 is the most species-rich within Triplectidinae, comprising about 90 species. Eight species have been recorded so far in Brazil, mainly distributed in the Southeast Region, and only one species has been recorded from the North Region. In this paper a new species of Triplectides is described and illustrated, Triplectides nessimiani Desidério & Pes sp. nov., based on adult males from Serra do Aracá, Amazonas, Brazil. We also provide the first record for Brazil of T. neblinus Holzenthal, 1988 and T. nevadus Holzenthal, 1988. In addition, an updated identification key to Triplectides species with occurrence in Brazil is presented.