A 56-year-old woman with fever, sore throat and productive cough was referred to our hospital, where mild community-acquired pneumonia was diagnosed. Sputum smears revealed Gram-negative coccobacilli. Treatment with ceftriaxone was initiated, but symptoms continued without progression to respiratory failure or bacteremia. As sputum cultures identified Acinetobacter baumannii, antibiotics were changed to levofloxacin, resulting in complete remission. A. baumannii is a very rare cause of community-acquired pneumonia in Japan. However, in cases of pneumonia where Gram-negative coccobacilli are identified and prove resistant to initial treatment, the possibility of A. baumannii pneumonia should be kept in mind even for healthy subjects with low severity score.