OBJECTIVE: To evaluate the clinical efficacy of a new formulation of albendazole emulsion (AbzE) in cases of liver cystic hydatidosis. METHODS: Two regimens of AbzE (10 mg.kg(-1).d(-1) and 12.5 mg.kg(-1).d(-1)) were given to 212 patients with liver cystic hydatidosis in courses ranging from 3 months to more than one year. Assessment of drug efficacy was essentially based on imaging signs with ultrasonography as the main tool. Assessments were performed at the end of different courses and in the follow-up study of 1 - 4 years after the cessation of therapy. RESULTS: At the end of therapeutic courses, the overall cure rate of the 212 cases was 74.5%, with a 99.1% effective rate. In the follow-up study, the cure rate was 83.1%, effective rate was 89.3%, ineffective rate was 0.6%, and recurrence rate was 10.2%. The highest cure rate was observed in cases receiving AbzE 12.5 mg.kg(-1).d(-1) for 9 months. Retreatment of recurrent cases with AbzE obtained satisfactory results. CONCLUSIONS: AbzE surpassed other currently used antihydatidosis drugs or formulations with its promising efficacy and mild side effects, and could be recommended as a drug of choice in the treatment of cystic hydatidosis.