A revision of the family Tetranychidae in Brazil (Arachnida: Acarina). In our recent paper: "Contribuição ao conhecimento da familia Tetranychidae no Brasil", published as a thesis we have reviewed the tetranychid mites found in this Country. The present work is part of that contribution. The following subjects are dealt with in this paper: List of genera, subgenera and species occuring in Brazil, with reference to the host plants and geographical distribution; key to sub-families, tribes and genera of the family Tetranychidae; keys for separating the species found in the Country; list of host plants. Tribe Porcupinychini Gutierrez, 1969 being considered a synonym of Histrichonychini Pritchard & Baker, 1955. Genus Anatetranyohus Womersley, 1940 and the species Tetranyohus yusti McGregor, 1955 and Oligonychus mangiferus (Rahman & Sapra, 1940), related by Flechtmann, 1967, are here considered misidentifications.