A prospective investigation of patients admitted to the local hospital during a period of one year was undertaken. A total of 107 patients participated. 50% of the cases of pneumonia were found by Streptococcus pneumoniae. The diagnosis was established partly by demonstration of antigens and increase in antibody titre and also employing the traditional methods: Blood culture, microscopic examination and culture of the expectorate or tracheal secretion. 70% of the patients were over the age of 60 years. The mortality was found to be 17%. The difficulties in etiological investigations of infections in the lower respiratory tract are discussed.