Sampling carried out during the winter-spring period from 2005 to 2011 has made it possible to identify 90 Mastogloia taxa present on sandy bottoms located in the sublittoral zone (first ten meters below the water surface) along the coasts of Guadeloupe, Marie–Galante and Martinique (French Lesser Antilles Islands, Caribbean Sea). The purpose of the present work is to provide a light microscopy–based account of Mastogloia taxa found in those three islands during the studied sampling period.