Cefmetazole was administered to 10 patients; 5 acute cholecystitis, 4 acute peritonitis and 1 periproctitis. 2. Cefmetazole was given by drip infusion at a daily dose of 2 to 4 g. 3. Clinical response was excellent in 3 patients, and good in other 7 patients. 4. No clinical adverse effect was recognized except the increase of GOT and GPT in 1 patient.