BACKGROUND Biliary cystadenomas of the liver are rare benign tumors prone to malignant alteration so that a total excision is recommended. OBJECTIVE The aim of the paper is to present our experience in treatment and to evaluate whether a simple ablation represents the appropriate treatment. METHODS Over a 10-year period 25 patients (24 women) of the average age of 58 years suffering from cystadenomas of the liver, 18 in the right, 4 in the left and 3 in both lobes of the liver were operated. Twenty-three patients had a single lesion, while two patients had 3 and 6 lesions, respectively. Pain was present in 20, occasional vomiting in 4, discomfort in 2 and a sense of fullness in 2 patients.Three patients were jaundiced, 1 due to cystadenoma of the liver, 2 due to concomitant tumors of the head of the pancreas, while 5 patients had concomitant diseases. RESULTS A total ablation was performed in 22 patients, left lateral bisegmentectomy in 1 and partial excision in 2 patients. Six additional procedures were performed. Five cystadenomas of the liver had,,ovarian like" stroma, all in women. A focal malignant alteration was found in 2 patients aged 66 and 79 years, respectively. Recurrence was registered in 1 female patient in whom a partial excision had been done. Two patients with concomitant malignancy and 1 patient who developed malignant histiocytosis six months after surgery, died after 1, 2 and 3 years, respectively. CONCLUSIONS Biliary cystadenomas of the liver may be misdiagnosed as simple liver cysts, so that ,,frozen section" histology is highly recommended. In most cases the tumor may be successfully treated by ablation up to the healthy liver tissue. Major liver resections are rarely necessary.