A new species of the diplocentrid scorpion of the genus Didymocentrus Kraepelin, 1905 is herein described from the Lesser Antillean island of Martinique. It long remained misidentified as Didymocentrus lesueurii (Gervais, 1844), the only species of this genus inhabiting the adjacent island of Saint Lucia. The direct comparison of adults of both sexes from these two islands revealed solid morphological characters, which warrant their recognition as two different taxa. Each one is endemic from a single major island, where it is widespread even in its satellite islets. This addition raises the known composition of the genus to 12 species, 10 of them exclusively Antillean.