Based on the examination of types and additional specimens, currently 21species and 3 newly described taxa of Prionolejeunea are recognized; 26 names are proposed as new synonyms. Prinololejeunea is characterized by the following features: leaf margins toothed by conically projected cells crowned by a small papilla, lobules with a proximal hyaline papilla, absence of ocelli, 2- keeled perianths and occasionally lejeuneoid subgynoecial innovations. The greatest diversity of this Afro- American genus is found in the Americas, where it is represented by 22 species. Only two species are known from Tropical Africa. The species of Prionolejeunea are usually epiphyllous or corticolousepiphytes in moist lowland to lower montane rain forests. Phyloge ne tic analyses based on morphological evidence and trnL- trnF spacer and nrITS region sequences indicatethat the trnL- trnF data set supports the monophyly of Prionolejeunea and demonstrates that Cyclolejeunea is the most closely related genus. A key to the species, as well as morphological descriptions, illustrations, and distribution maps for each species are presented.