Many clinical trials have been conducted in which hyperthermia has been used in conjunction with chemotherapy in the management of unresectable solid tumors. In this regard, promising Phase Ⅱ trial results have been reported. We experienced three cases of unresectable colorectal cancer in which the use of hyperthermia sensitized the effects of anticancer drugs and enabled cancer control. It is considered that systemic chemotherapy with the use of hyperthermia, at the right time, will lead to better treatment outcomes.