Objective: To investigate the clinical value of contrast-enhanced ultrasonography (CEUS) immediately after radiofrequency ablation (RFA) for malignant hepatic tumors. Methods: Sixty consecutive patients with malignant hepatic tumors (76 lesions) admitted between October 2014 and December 2015 in Xiangya Hospital were randomly designated to study group and control group with 30 cases in each group (41 lesions in study group, 35 lesions in control group). All patients underwent percutaneous RFA under real time ultrasound guidance. In patients in study group, CEUS was performed immediately (within 5-10 min) after RFA, and supplementary ablation was conducted immediately for the tumor residues until no residue was detected by contrast examination, while immediate CEUS was not performed in those in control group. Patients in study group underwent CEUS again at 36-48 h after RFA, and patients in both groups underwent CEUS together with contrast-enhanced CT or MRI as well as detection of liver function parameters and tumor markers at 1 month after the RFA. Results: A total of 5 tumor residues were found by immediate CEUS in 5 patients of study group , and supplementary treatments were performed. By review examinations for the two groups at 1 month after RFA, one tumor residual (1/41) was found in study group and 7 tumor residuals (7/35) were found in control group, and the complete ablation rates between study group and control group were statistically different (96.7% vs. 80.0%, P<0.05). In study group, the thickness of the hematoma or edema around the ablation zone detected by CEUS in arterial phase examination immediately after RFA and 36–48h later was (6.89±2.73) mm and (4.68±2.05) mm respectively, and the difference had statistically significant (P<0.05). Conclusion: CEUS immediately after RFA can timely detect the tumor residuals and direct supplementary therapy, and effectively increase the complete ablation rate.