A 49-year-old male presented with fever and right back pain for one week. (a) A lager multiloculated liver abscess in the right hepatic lobes was shown by enhanced CT, and small amount of fluid can be seen in the left chest. (b) Catheter was placed under CT guidance, without injection of oxygen-ozone gas. (c) Three-week follow-up showing that abscess was not fully absorbed. (d) Abscess was fully absorbed after eight weeks.