Metazoan infracommunities of Menticirrhus ophicephalus from the south Pacific Ocean and M. americanus from the south Atlantic Ocean were analyzed and compared. The metazoan parasite infracommunities of M. ophicephalus showed higher values of total number of parasite individuals/host and parasite species richness than that of M americanus, but M. americanus showed higher values of parasite species diversity. The infracommunities of ectoparasites showed higher values of total number of parasite individuals/host, richness, and frequency of dominance in M. ophicephalus; in contrast, endoparasites showed higher values of these infracommunity descriptors in M. americanus. Ecological analysis of the marine fish parasite infracommunities using the total number of components (ecto- and endoparasites) could hide some patterns of the community structure; thus, a separate analysis of only ecto- or endoparasites is recommended. Additional studies monitoring the influence of the "upwelling ecosystem" and the El Niño-Southern oscillation event on the fish parasite communities are necessary to determine the real influence of these ecological disturbances on the structure of fish parasite communities in South America.