Ten species of benthic algae, principally associated with coral reef habitats, are newly reported for the Puerto Rican marine flora. These include eight Rhodophyta: Renouxia antillana, Lithophyllum congestum, Lithothamnion occidentale, Metapeyssonnelia corallepida, Maripelta atlantica, Pihiella liagoraciphila, Antithamnionella graeffei, and Myriogramme prostrata; one Heterokontophyta: Dictyota pfaffii; and one Chlorophyta: Caulerpa nummularia. Maripelta atlantica and Myriogramme prostrata are additionally reported for the Cayman Islands and from Venezuela, respectively.