Samples of black grouper, Mycteroperca bonaci, totalling 161 specimens, were collected at 3 protectednatural areas in Yucatán, Mexico: Reserva de la Biosfera Ría Celestún (RBRC), Reserva Estatal de Dzilam (RED),and the Parque Nacional Arrecife Alacranes (PNAA). In this study, we present the results of a survey of the metazoanparasite fauna of these fishes, together with a checklist of the metazoan parasites recorded previously from blackgrouper in the Gulf of Mexico and the Caribbean Sea. Twenty five taxa were found in the survey (21 adults and 4larval stages). Nineteen taxa represent new host records for M. bonaci, increasing the total number of parasite taxarecorded for this host species to 59 in the geographic area referred above. Differences in species composition andinfection parameters of each group of parasites are presented and discussed.