We report a 4-year-old girl with disseminated cystic echinococcosis in the lung and the liver and a solitary cyst in the left kidney. Mebendazole therapy produced complete resolution of the lung and kidney cysts. In the liver, most of the smaller cysts disappeared, whereas the larger cysts showed only partial response and required surgical excision. Our experience reinforce the finding in previous reports that long term medical treatment of cystic echinococcosis with mebendazole can be lifesaving in cases that are unmanageable by surgical treatment.