Community acquired pneumonia remains as a common and serious world-wide medical problem with high mortality, morbidity rates and big economic losses. We have studied the efficacy of a three day course of azithromycin in the outpatient management of community acquired pneumonia in a prospective, open and noncomperative study. 24 patients with clinical and radiological evidence of pneumonia were entered into the study. Microbiological evaluation was performed to 18 patients who may produce sputum. Abundant gram-positive diplococci were remarkable in 12 patients and 5 sputum cultures were positive for bacteriological growth. Patients who satisfied the study entry criteria received a total of 1.5 g azithromycin given as single daily doses of 500 mg for three days. A satisfactory clinical response to azithromycin treatment was reported in all the patients. Azithromycin is well tolerated by the patients due to its short course administration with no interruption of the treatment in any patient. As a result our study showed that a three day course of azithromycin is effective in the treatment of mild to moderately severe community acquired pneumonia in an outpatient setting.