We report a case of eosinophilic cystitis caused by vesical sparganosis. The patient had a history of eating raw frogs and presented with a mass in the bladder associated with peripheral eosinophilia and increased serum antibody titer against sparganum. Pathologically, a characteristic sinuous necrosis representing worm tracks was noted with massive diffuse infiltration of eosinophils in the wall of the bladder. The serum titer of sparganum-specific antibody returned to normal after surgical resection of the lesion. This finding emphasizes the importance of suspecting parasitic origin in cases of eosinophilic cystitis with a history of raw meat ingestion in endemic areas.