Cefotaxime (CTX) was administered to 130 children with various bacterial infections of 41 to 400 mg/kg/day for 2 to 21 days. The clinical effect of CTX was very satisfactory in respiratory tract infection, urinary tract infection and meningitis. The overall clinical effect was excellent in 59, good in 39, fair in 17 and failure in 8 with effective rate of 79.7%. During this therapy, side effects were seen in 3 cases, diarrhea in 1 and rash in 2. Abnormal laboratory findings were seen in 5 cases, elevation of GOT in 1, GOT, GPT and A1-P in 1, GOT, GPT and T. Bil. in 1, elevation of BUN, increase of number of basophils and albuminuria in 1 and observation of albuminuria in 1. The above results demonstrate that CTX is a clinically useful antibiotic for the therapy of pediatric infections.