Pyogenic hepatic abscess is a rare disease and its prognosis is unfavorable because of serious conplicationts, including sepsis and DIC. Recent progress in ultrasound and computed tomographic techniques enable us to diagnose hepatic abscess at an early stage, making it acurable disease. We have experienced 4 cases of diabete smellitus complicated by pyogenic hepatic abscess over the last 10 yenrs. There were 3 manes and 1 female with an age range of 38-66 years. Three of the 4 patients had a past history of cho1edocholithiasis and cholecystectomy. Clinical features were fever, nausea, vomiting and genernl malaise. All of the patients had poor blood sugar control. Abscesses were solitary and located in the right lobe of liver in all 4 patients. Aerobic bacteria including E. coli and Klebsiella pneumoniae were detected in the aspirated pus in 3 of the 4 patients. Gas formation was found in one patient and may have resulted from anaerobic glycolysis. Transhepatic abscess drainage and chemotherapy dramatically improved hepatic abscess. These results indicate that early diagnosis by an ultrasound and computed tomograpy approach is of great value in treating pyogenic hepatic abscess.