The genus Kempnyia is conprised of 41 described species, six described here, 24 species based on males and females, nine based on nymphs, twelve based on males and five based on females. The genus can be found from the South to the highlands of central Brazil and throuthout the coast, from Rio Grande do Sul State to the south of Bahia State, with an isolated record in Venezuela. We present the diagnosis of all species of the genus, six new species and four nymphs are described as well as complementary descriptions of some species already known. Additionally an identification key to adult males and a phylogenetic hypothesis for the genus are presented. The monophyly of the genus was corroborated in all cladistics analysis tested here. The topology which probably represents the phylogeny of