OBJECTIVE To investigate the epidemiology and clinical characteristics of community acquired pneumonia (CAP) in children before the introduction of the 7-valent pneumococcal vaccine in the national vaccination programme. METHODS For the period 21 May 2003 to 20 May 2005 hospitalization rates for pneumonia in children were obtained from retrospective studies of medical journals. Pneumonia was also studied prospectively in children less than sixteen years old referred to Ullevål University Hospital (Oslo) in the same time period. RESULTS The overall observed hospitalization rate of pneumonia was 14.7/10 000 (95% CI: 12.2-17.1), for children under five it was 32.8/10 000 (95% CI: 26.8-38.8), and for children under two 42.1/10 000 (95% CI: 32.0-52.3). In the clinical study 123 children, of whom 59% (73) were boys, met the inclusion criteria and were enrolled. Only 2.4% (3) had pneumonia complicated with pleural effusion and in general few complications were observed. No patients required assisted ventilation, and none were transferred to the intensive care unit. Penicillin was effective as treatment for pneumonia. CONCLUSIONS Pneumonia, seen in a paediatric department in Oslo, is a common but benign disease. Penicillin is effective as treatment for pneumonia in Norwegian children.