Ophiocaryon barnebyanum from the Serra da Neblina (Venezuelan-Brazilian border) and O. neillii from southern Ecuador are described and illustrated, and their morphological relationships with allied species are discussed. Ophiocaryon barnebyanum is morphologically similar to O. duckei, but it differs by its larger leaves, leaflets, petioles, petiolules, and inflorescences, the higher number of secondary veins, and the ciliate sepals. Ophiocaryon neillii is a small tree related to O. klugii but differs by its smaller leaflets, petiolules and inflorescences, fewer secondary veins, lanceolate-acuminate sepals, and orbicular staminodes. An updated key to the species of Ophiocaryon is provided.