Adult yellowfin snook (Centropomus robalito) were collected between January and May 2008 (dry season), to assess the consistency (repeatability) of the species composition and richness of their helminth communities in 4 coastal lagoons from Guerrero, Mexico. Fifteen species of helminth were identified: 4 Monogenea, 6 Digenea, 1 Acanthocephala, and 4 Nematoda. The helminth communities in the 4 lagoons consisted mainly of marine autogenic species, were poor in richness and diversity, and exhibited low qualitative similarity at the component level (29.5% to 62.1%) and the infracommunity level (0.48 ± 0.30 to 0.69 ± 0.19), indicating that species composition and richness of the helminth communities of C. robalito are not predictable at a spatial scale. Significant nestedness occurred in the infracommunities of all lagoons, as well as among 2 sampling periods in Tres Palos Lagoon, suggesting a certain degree of structure in species composition in infracommunities in space and time.