The polychaetes epibiontic on the mollusk Spondylus americanus Hermann, 1781 were extracted from mollusks hand-collected at a depth of 10-30 m in Mochima National Park, Venezuela (10º21’00” N - 63º23’36” W), using scuba diving gear. Forty-three polychaete species were identified on the 32 bivalve specimens analyzed. The Serpulidae included 17 especies, Eunicidae six and Terebellidae four species. The most abundant species were Hydroides dirampha Mörch, 1863, Pileolaria militaris Claparède, 1868 (Serpulidae), and Notaulax nudicollis Krøyer, 1856 (Sabellidae). Their geographic affinitie were: 51.3% Atlantic, 28.2% widely distributed, 17.9% Amphiamericans, and 2.6% have a disjunct distribution.