Non-parasitic liver cysts represent a frequent pathology, but rarely they cause compressive symptoms so to require a suitable treatment. The Authors report a case of solitary large cyst localized in the left liver lobe, causing compressive symptoms in a cardiopathic old woman in whom surgical treatment was contraindicated. The treatment consisted in US-guided percutaneous puncture, decompression and sclerotherapy by 300 cc of ethylic alcohol (90 degrees). The patient showed a moderate alcoholic intoxication, associated with fever. This treatment been repeated fifteen days after for the large dimension of the cyst. Twelve months later the results were excellent with a complete relief of compressive symptoms and a remarkable reduction of the cyst at the CT scan. The Authors conclude that, in case of non operable large liver cysts, percutaneous ethanol injection is the treatment of choice, with low cost and morbidity, and mild recurrence rate.