In June 2014, 30 marbled toads (Incilius marmoreus) from Oaxaca, Mexico were examined for helminths. We collected a total of 3,783 helminths belonging to 13 taxa: 4 digenean, 1 cestode, 1 acanthocephalan, and 7 nematoda. The nematode Physocephalus sp. was the most prevalent (63.3%) followed by Aplectana sp., which had the highest mean intensity (114.3) and mean abundance (63.8) that we recorded. The taxonomic composition of I. marmoreus mainly consists of generalist helminths, with nematodes being the predominant parasites found, confirming the terrestrial habits of this toad. The main route of helminth acquisition was ingestion of larvae and/or intermediate hosts, a process that also likely contributes to the high abundance of individuals in the toads. The knowledge of the helminth fauna associated to the 39 toad species distributed in Mexico is scarce and fragmentary, and our study presents results for only the second bufonid species studied in this region.