From the region of Nosy Bé, Madagascar, three new species of copepods belonging to the lichomolgid genus Macrochiron, associated with plumulariid hydrozoans, are described: M. lytocarpi and M. valgum from Lytocarpus philippinus and M. rostratum from L. philippinus and L. spectabilis. Certain features of the external anatomy of Macrochiron are briefly discussed.