In the present work a delimitation of the genus Phaseolus L. was made. This genus comprises seven sections: Ceratotropis Pip., Cochliasanthus Pip., Euphaseolus Benth., Lasiospron Pip., Macroptilium Benth., Microcochle Pip. and Sigmoidotropis Pip. The work is provided by a diagnosis of each section, giving a relation of the Brazilian species and its scientific synomymy. The author concluded by the validity of the section Macroptilium Benth., and reduced the section Leptospron Benth. as synonym of the section Euphaseolus Benth.