Gas-forming pyogenic liver abscess is considered to be a very severe form of pyogenic liver abscess and carries a high mortality. Klebsiella pneumoniae is the most common pathogen responsible for the disease. We present a case of gas-forming pyogenic liver abscess in a 53-year-old man with diabetic mellitus. The patient got improved with utilizing ultrasound guided percutaneous drainage, third generation cephalosporin and insulin control for hyperglycemia. He was discharged uneventfully after a 12-day hospitalization.