135 patients have been evaluated to improve methods of diagnosis and treatment of nonparasitogenic liver cysts. Ultrasound, ETA, indirect hemagglutination were used for differential diagnosis. Target thin-needle aspiration biopsy under the ultrasound control with subsequent cytologic studies was performed in all the patients. Most informative data have been provided by enzyme immunoassay and indirect hemagglutination. 118 patients have been successfully treated with puncturing, drainage and sclerosing of the cavity walls with 96% ethanol. There were no cases of recurrence, morbidity, mortality. Surgery has not been performed in 17 patients with small-size cysts.