Fifteen cases of alveolar hydatid disease were treated with albendazole in the dosage of 20 mg/kg/d x 30 days for 12-60 courses. All cases were followed up 1-5 years (average 38 months) by ultrasonic scanning of liver and chest X-ray films. One patient whose hepatic lesion was converted into fibro-calcific after treatment was apparently cured. Twelve patients were symptomatically improved: jaundice (4 cases) and hemoptysis (2 cases) disappeared, with reduction in size of lesions in the liver and lung. Two patients in the late stage of disease with huge and extensive nodular masses in both lobes of the liver were not improved. Evidently, albendazole is effective in the treatment of alveolar hydatid disease. Early diagnosis and early treatment are to be emphasized.