Twenty two spccies of zooxanthellate sc1eractinian coral s from the Pacific of Costa Rica are described and illuslraled with macrophotographs. Keys lO the genera and species are inc1uded. Their geographic distributions in Costa Rica and world-wide are noted, as well as aspects of lhe natural history of the species. Sixteen species have wide distributions, from the Red Sea or Indian Ocean to the Pacitlc coast of America, two species are endemic to the eastern Pacific , four species are found only in the Pacific Ocean: there are no species in common with the Caribbean-Atlantic. Two species, Leptoseris scabra and Pavona xarifáe, are new records for the eastern Pacifico
Keywords: corals, eastern pacific, taxonomy, marine biodiversity