As a result of the treatment of Protomegabaria (Phyllanthaceae) for the Flore du Gabon, some morphological features are highlighted. The two species of the original publication of the genus, Protomegabaria stapfiana (Beille) Hutch. and P. macrophylla Hutch., currently synonymised under the former name, are distinct which is illustrated and demonstrated in the key to the species. Protomegabaria stapfiana and P. macrophylla are lectotypified. Distribution maps of the species are presented and special attention is given to the disjunct area of the third species Protomegabaria meiocarpa J. Léonard.