We investigated the usefulness of the novel oral carbapenem antibiotic tebipenem pivoxil (TBPM-PI) for treating bacterial pneumonia in children. Sputum and nasopharyngeal swabs were collected simultaneously, and causative organisms were identified by conventional bacterial culture together with exhaustive bacterial and viral identification by real-time polymerase chain reaction (PCR). The subjects were eight patients diagnosed with mild or moderate pneumonia at Sotobo Children’s Clinic Outpatient Department between October 2006 and June 2007. TBPM-PI was administered at the recommended clinical dose of 4 mg/kg b.i.d. to five patients and at a high dose of 6 mg/kg b.i.d. to three patients. Sputum was collected from all patients, and 11 strains were detected from washed sputum culture. Causative organisms were mainly Streptococcus pneumoniae (3 strains) and Haemophilus influenzae (6 strains), and nasopharyngeal swabs showed the same organisms as coughed-up sputum. Real-time PCR for individual viruses and Mycoplasma pneumoniae identified four cases of only bacterial infection, one case of M.pneumoniae coinfection, two cases of viral coinfection, and one case of both viral and M.pneumoniae coinfection. The clinical results indicated efficacy in all patients, and causative organisms were 100% eliminated. In the four patients with only bacterial infection, the average fever of 38.9°C at the start of treatment normalized the following day, showing excellent efficacy. No clinically problematic adverse events occurred, and compliance was good. We consider that these cases provide valuable insights into the identity of pathogenic organisms of pneumonia in children and the possible role of TBPM-PI in outpatient treatment.