Children with acute infections were treated with cefpodoxime proxetil (CPDX-PR, CS-807), a new oral cephalosporin. 1. A girl of 4 years old, weighing 17 kg, and another girl of 12 years old, weighing 33 kg, were administered orally each 3 mg/kg of CPDX-PR. Blood levels of CPDX reached peaks of 1.39 and 2.26 micrograms/ml at 4 hours-post-dose, and T1/2's were 2.09 and 2.63 hours, respectively. Cumulative urinary recovery rates for 8 hours were 57.3 and 80.9%, respectively. 2. A total of 30 patients was treated with CPDX-PR. These patients included 10 with acute tonsillitis, 6 with acute bronchitis, 5 with bronchopneumonia, 2 with scarlet fever and 2 with urinary tract infections, and one each with acute pneumonia, acute otitis media, acute otitis media plus sweat gland abscess, staphylococcal scalded skin syndrome and acute lymphadenitis. The treatment was effective in 27 cases out of 29 (except one with an unknown response) with a clinical efficacy rate of 93.1%. 3. Bacteriological responses to CPDX-PR were as follows; eradication of pathogen in 7, and unknown in 2 out of 9 cases from whom pathogens had been isolated prior to the treatment. 4. As a side effect, diarrhea was observed in 1 patient, but it was possible to continue the treatment. With regard to laboratory tests, a slight elevation of GOT and slight elevations of GOT and GPT were found in 1 case each.