Aeromonas hydrophila is a low-virulence gram-negative bacillus. It has never been reported as a pathogen of non-traumatic acute osteomyelitis in a cirrhotic patient. Herein, we reported on a case of decompensated liver cirrhosis with Aeromonas hydrophila infection presenting as acute gastroenteritis and non-traumatic acute osteomyelitis. It has been shown that Aeromonas bacteremia usually affects immunocompromised subjects, such as those with liver cirrhosis. Non-traumatic acute osteomyelitis should be highly suggested when a cirrhotic patient with Aeromonas bacteremia presents with severe low back pain and no associated trauma.