Here we revise description of the Neotropical genus Stibasoma Schiner (Diachlorini - Tabaninae), including redescription of 15 species that range from Mexico to northern Argentina: S. apicimacula Fairchild, S. aureoguttatum Krober, S. bella Limeira de Oliveira & Rafael, S. bicolor Bigot, S. chionostigma (Osten Sacken), S. currani Philip, S. festivum (Wiedemann), S. flaviventre (Macquart), S. fulvohirtum (Wiedemann), S. giganteum (Lutz), S. leucopleurale Barretto, S. lutzi Barretto, S. panamensis Curran, S. theotaenia (Wiedemann) and S. willistoni Lutz. The taxon S. bifenestratum Philip is revalidated. Two new species are described from the Amazon: S. manauensis sp. nov. and S. ruthae sp. nov. Previously unknown males are described in S. bifenestratum, S. currani, S. festivum and S. fulvohirtum. Two subspecies are not recognised: S. festivum dyridophorum and S. flaviventre pulla. A dichotomous identification key based on external morphological characters is provided.