In this study, 130 patients with community-acquired pneumonia were prospectively investigated between January 1996 and February 1999. The aim of this study was to determine the initial treatment according to the causative agents and prognostic factors. The study group included 78 (60%) men, 52 (40%) women with a mean age of 40.5 ± 13.6 years (range 14-75 years). Underlying diseases were found in 45 (35%) cases. The major underlying diseases were chronic obstructive lung disease (16%) and diabetes mellitus (10% The cause of pneumonia was diagnosed in 57 (44%) cases, and the most common pathogen was Streptococcus pneumoniae (17%), followed by gram negative enteric rods (8%), Mycoplasma pneumoniae (7%), Chlamydia pneumoniae (5%), Staphylococcus aureus (4%) and Legionella pneumophila (3%). The overall death rat was 3%. Fifty two (40%) patients were hospitalized. In patients with community-acquired pneumonia, ant biotic chemotherapy was carried out according to the etiologic agents and the guidelines of the America Thoracic Society and the Turkish Thoracic Society Community-acquired pneumonia remains a major health-care issue. The development of country-specific guidelines is an attempt to standardize initial management. But ideally, all such guidelines should be validated by appropriate prospective studies. Further studies are also required to provide data on community-acquired pneumoniae in patients who do not require admission to hospital.