Cefprozil granule preparation was administered orally to 16 patients (ages ranging 8 months to 9 years and 6 months) with pediatric bacterial infections at daily dose levels between 29.4 and 35.7 mg/kg divided into 3 or 4 doses. The following results were obtained. 1. Sixteen patients including 5 with pharyngitis, 3 with tonsillitis, 3 with lacunar tonsillitis, 2 with pneumonia, 2 with contagious impetigo and 1 with scarlet fever were treated. Clinical effects were excellent in 9 cases and moderate in 7, with an overall efficacy rate of 100%. 2. Organisms suspected as pathogens included 17 strains (10 strains of haemophilus influenzae, 2 of Haemophilus parainfluenzae, 3 of Streptococcus pyogenes and 2 of Staphylococcus aureus). Bacteriologically, eradication of pathogens were observed for 11 strains, but no changes were obtained for 5 (all Haemophilus), and unknown results were obtained for 1, thus the eradication rate was 68.8%. 3. No side effects were observed. Abnormal laboratory test results included 2 cases of increase in platelets, and 2 of increase in eosinophils, but those were not significant. 4. No refusal of the drug occurred due to its taste or odor.