Since April 1990, multiple metastatic liver tumors have been treated with intraoperative ultrasound-guided microwave tumor coagulation (MTC) in combination with postoperative intraarterial chemotherapy. Twenty-four patients have been enrolled in this therapeutic modality and two of five patients treated in 1990 achieved long-term survival. In case 1, a 67-year-old woman was diagnosed as bearing gastric leiomyosarcoma with multiple liver metastasis. Total gastrectomy was performed, and six hepatic lesions were treated by MTC along with implantation of an intraarterial reservoir. Postoperative intraarterial chemotherapy was administered in a selective or subselective manner. Her survival time was 4 years and 6 months. In case 2, a 47-year-old man was diagnosed as having liver metastasis from descending colon cancer 1 year and 5 months after left hemicolectomy. When he was laparotomized for the treatment of adhesive ileus, three metastatic liver tumors were treated with MTC. Afterward, he underwent hepatic resection, intraarterial and intraportal chemotherapy. He survived for 5 years and 5 months after being diagnosed with liver metastasis. MTC is one of the useful modalities for the treatment of multiple liver metastasis.