Two new genera in the spider family Trechaleidae, Trechaleoides and Paratrechalea, are described. The females of the two known species of Trechaleoides, T. keyserlingi (F.O.P.-Cambridge) (type species) and T. biocellata (Mello-Leitão) are redescribed and their respective males are described for the first time; both are transferred from Trechalea. Two additional previously described species, also both transferred from Trechalea, are herein placed in the genus Paratrechalea are redescribed from their types, i.e., the female of P. ornata (Mello-Leitão) (type species) and male of P. wygodzinskyi (Soares & Camargo). The male of P. ornata is described for the first time. Four new species of Paratrechalea, P. longigaster, P. galianoae, and P. azul from females, and P. saopaulo from males and females are described. The immature specimen historically regarded as the holotype of Trechalea longitarsis (C.L. Koch) and regarded as a mistaken identity, is an unidentified species of Trechaleoides. The female holotype of Trechalea limai Mello-Leitão is confirmed to be lost but is considered to be a member of the genus Paratrechalea based on a study of the original description.