Parasitic and tropical diseases are relatively rare in Japan. However, physicians have to realize that a patient may visit your hospital today, who is infected with a potentially fatal parasite. This review focuses on the treatment of the domestic and imported parasitic infections in Japan. Many of the drugs against parasitic diseases, especially imported protozoan diseases, have not been approved, nor have been covered by the National Health Insurance Policy. Therefore, patients who need pharmacotherapy with an unapproved drug have to be treated in one of the hospitals of the Research Group on Chemotherapy of Tropical Diseases, which imports effective drugs against major tropical diseases.