The genus Triaenodes as it occurs in the Neotropics is diagnosed and discussed in the context of the world fauna. Twenty new species are described and illustrated: T. acanthus (Mexico), T. chirripo (Costa Rica), T. clauseni (Costa Rica, Nicaragua, Panama), T. cuyotenango (Guatemala), T. flintorum (Mexico), T. guadaloupe (Panama), T. hodgesi (Ecuador), T. hornitos (Panama), T. kilambe (Nicaragua), T. mexicanus (Mexico), T. moncho (Costa Rica), T. morai (Costa Rica, Nicaragua), T. nicaraguensis (Nicaragua), T. oaxacensis (Mexico), T. tajo (Costa Rica), T. talamanca (Costa Rica), T. tapanti (Costa Rica, Panama), T. tico (Costa Rica, Panama), T. tuxtlensis (Mexico), and T. woldai (Panama). In addition, 4 previously described species are redescribed and figured: T. abruptus Flint 1991 (Colombia), T. anomalus Flint 1967 (Nicaragua, Mexico), T. delicatus Nav s 1924 (Costa Rica, Panama), and T. peruanus Flint & Reyes 1991 (Colombia, Ecuador, Peru). The status of Triaenodes columbicus Ulmer 1909, is discussed. The larval and pupal stages of a Costa Rican species and the females of 9 species are described, representing the first descriptions of these life history stages for Neotropical Triaenodes. The genus Ylodes Milne is returned to synonymy with Triaenodes, as a subgenus. A key to the males of Neotropical Triaenodes is provided.