Coral reefs are ecosystems with great biodiversity and architectural complexity. Among these, marine fungi constitute one of the least studied groups, despite being potentially an inexhaustible source of bioactive metabolites. For this reason, in this research, we evaluate the antiproliferative activity of 52 fungal strains associated with marine organisms such as algae and coral collected from four islands located in the National Park Sistema Arrecifal Veracruzano, Mexico. One hundred four chloroform:methanol extracts corresponding to the culture broth, and biomass produced from each fungal strain was obtained from these. Subsequently, they were evaluated against six human solid tumor cell lines (HBL-100, HeLa, SW1573, T-47D, WiDr, and A549). The outcome was that six extracts showed activity against at least one cancer cell line. The identity of these fungi corresponded to the genera Nigrospora, Pestalotiopsis, Cladosporium, and Ochroconis according to their morphological and molecular analysis. In this sense, the strain found to have the highest antiproliferative potential [GI50 (μg mL-1) 4.6, 2.5, 8.0, 5.6, 52.0, 4.0] grouped phylogenetically with a species of Nigrospora sp. The preceding confirms that ecosystems provide.