A 69-year-old male, a heavy user of alcohol, was admitted with right middle-lobe pneumonia. Because Klebsiella ozaenae was detected in his sputum twice, we diagnosed lobar pneumonia by K. ozaenae. We administered meropenem (MEPM) and pazufloxacin (PZFX), but the lobar pneumonia changed into necrotizing pneumonia. Because general condition, respiratory condition, and inflammatory reaction (C-reactive protein level and leukocyte count) were improving, we pursued the treatment for MEPM and PZFX. As a result, the right cavitary pneumonia was gradually downsized, the right cavity almost faded away, and bronchial dilatation made an appearance. The right pneumonia then became organized, and pneumatocele made an appearance. Community-acquired pneumonia caused by K. ozaenae is rare, and this case shows that it causes necrotizing pneumonia, as it does with Klebsiella pneumoniae.