Freshwater fish, specifically loaches, are potential hosts of Gnathostoma species. Consumption of uncooked freshwater loaches may result in cutaneous larva migrans. We report the case of a 70-year-old Taiwanese man who presented with a serpiginous skin rash on his abdomen. He had eaten live loaches intermittently (sometimes daily) for 5 months before his presentation. On histopathological examination, a transected parasite body and a headbulb were found in the mid-dermis. The parasite was confirmed as belonging to the genus Gnathostoma, most likely Gnathostoma doloresi. The patient recovered uneventfully without treatment, and had no symptoms at his 12-month follow-up visit.