This study examined gastrointestinal parasites of raccoon dogs in the Seosan reclaimed lands, Korea. We collected 882 raccoon dog fecal samples and examined them using a fecal flotation technique following standard procedures. Identification was based on the morphology and size of the parasite eggs and oocysts. Nine different helminth eggs and oocysts of Isospora spp. were identified. In total, 314 (35.5%) fecal samples were positive for gastrointestinal helminths or Isospora spp. Double (6%), triple (1%), and quadruple (0.3%) infections were observed. The rates of parasite infection in spring, summer, fall, and winter were 29.8, 20.7, 39.0, and 42.9%, respectively. These results indicate that raccoon dogs host diverse helminths and Isospora spp., posing a potential risk of transmitting parasites to domestic pets and residents in the area. Active epidemiological surveillance with modern molecular techniques and ancillary epidemiological tools is recommended.