To examine the efficacy of percutaneous MWA with artificial pleural effusion, we designed a case-control study, and compared the primary technique effectiveness rate, local tumor progression rate, and tumor-free survival rate between an artificial pleural effusion group and a control group which was matched in terms of tumor differentiation, tumor size, and tumor location. In previous studies [1, 3], tumor differentiation and tumor size were chosen as the independent prognostic factors affecting recurrence of hepatocellular carcinoma after microwave ablation treatment. Therefore, tumor differentiation and tumor size were selected as a matching standard to make sure that the two groups were balanced as far as possible. In addition, we matched tumor location between the two groups to compare complications after treatment. The results of our study showed that the primary technique effectiveness rate, the 1-, 2-, and 3-year local tumor progression rates, and the 1-, 2-, and 3-year tumor-free survival rates in the two groups had no significant difference. Therefore, percutaneous MWA with artificial pleural effusion for liver tumors located in the hepatic dome has a similar therapeutic effect to that of percutaneous MWA for liver tumors with good ultrasonic visibility.