The synopsis of Phyllanthus section Phyllanthus in Brazil treats 4 subsections (2 of them newly described) including 30 species. A new subsection Almadenses is described based on Phyllanthus almadensis Müll. Arg., a species from Bahia, Brazil with a unique growth pattern. Another new subsection Clausseniani is proposed; it includes 17 species, all endemic to Brazil. Seven new species in this subsection are described: Phyllanthus allemii, P. atalaiensis, P. caparaoensis, P. carvalhoi, P. mocotensis, P. piranii, and P. sincorensis. A key to the Brazilian sections of subgenus Phyllanthus is provided, as well as synoptic keys and descriptions for the two new subsections and subsections Niruri and Swartziani.