A new species, Diopatra marocensis, is described from the fine sand Abra alba community, Sidi Boulbra, south Moroccan Atlantic coast. The new species is a member of the D. cuprea complex and is characterized by having crescentic nuchal grooves, short ceratophores, a short branchiate region, four pairs of modified parapodia with bidentate pseudocompound hooks, pectinate setae with 11–20 teeth, limbate setae with conspicuously serrated shelf, and subacicular hooks from setiger 13–15. Eggs of Diopatra marocensis sp. nov. are deposited in the parental tube, where they undergo direct development and remain until the young consist of 32–34 setigers.