The survival of most patients with both unresectable hepatic and pulmonary metastases of colorectal cancer is poor. In this retrospective study, we investigated the efficacy of computed tomography (CT)-guided radiofrequency ablation (RFA) and systemic chemotherapy plus hepatic artery infusion of floxuridine (HAI-FUDR). Sixty-one patients were selected from 1,136 patients with pulmonary and hepatic metastases from colorectal cancer. Patients were treated with RFA and systemic chemotherapy plus HAI-FUDR (ablation group, n=39) or systemic chemotherapy plus HAI-FUDR (FUDR group, n=22). Patients in the two groups were matched by sex, age, number of metastases, and calendar year of RFA or FUDR. Survival data were evaluated by using univariate and multivariate analyses. Clinical characteristics were comparable between the two groups. Al patients in the ablation group underwent RFA and chemotherapy. Median fol ow-up was 56.8 months. The 1-, 3-, and 5-year overall survival (OS) rates were 97%, 64%, and 37%, respectively, for the ablation group, and 82%, 32%, and 19%, respectively, for the FUDR group. The 1-, 3-, and 5-year survival rates after metastasis were 97%, 49%, and 26%for the ablation group, and 72%, 24%, and 24%for the FUDR group, respectively. The median OS times were 45 and 25 months for the ablation and FUDR groups, respectively. In the multivariate analysis, treatment al ocation was a favorable independent prognostic factor for OS (P = 0.001) and survival after metastasis (P = 0.009). These data suggest that the addition of RFA to systemic chemotherapy plus HAI-FUDR improves the survival of patients with both unresectable hepatic and pulmonary metastases from colorectal cancer.