The presence of Parachromis managuensis has been reported for the first time in the Tres Palos Lagoon, State of Guerrero, on the coastal Lagoon of the Mexican Pacific slope. Two specimens (189 mm and 215 mm standard length) were caught by local fishermen from the community of San Pedro de Las Playas. A description of the morphological and meristic characters of the specimens is provided. The natural distribution of the species is from Honduras to Costa Rica and, as it is predatory and highly territorial, in conjunction with other introduced species, it can present a risk to native species and alter the biological dynamics in the lagoon system.