Emmotum Desv. ex Ham. is a Neotropical, primarily Amazonian and Guayanan genus (Icacinaceae) of 13 tree or shrub species, including a new species here described from Amazonas, Brazil, E. amazonicum Duno & Carnevali. A cladistic analysis of the 18 taxa of Icacinaceae including 13 of Emmotum was carried out using 41 morphological characters. The single most parsimonious tree shows Emmotum as a monophyletic group, strongly supported by nine synapomorphies, with Poraqueiba Aubl. as the sister group. In addition, two main groups are identified within Emmotum. These two groups laxly correspond with the 1872 classification of Engler: Emmotum sect. Brevistyla Engl. and Emmotum sect. Longistyla Engl. (= section Emmotum). The genus Pogopetalum Benth., synonymous within Emmotum, is lectotypified by P. orbiculatum Benth. (≡ E. orbiculatum (Benth.) Miers). We present a revision of Emmotum with information about nomenclature, distribution, ecology, local names, and uses.