Electrochemotherapy (ECT) is a new technique that enhances the antitumor effect of various anticancer agents by delivering high-voltage electrical impulses to the tumor. A rat squamous cell carcinoma and a hepatocellular carcinoma were transplanted into the tongues of rats and subjected to a) high-voltage electrical impulses 30 min after the injection of bleomycin, b) bleomycin treatment alone, and c) electrical treatment alone. A non-treated control group was also included. Following ECT, the tongue tumors were no longer visible from the 3rd day after treatment and histological examination revealed complete regression, whereas tumors that received either high-voltage impulses alone or bleomycin alone showed no detectable changes. The healing process following ECT progressed smoothly, including that of the normal tissue within the electrical field that was seriously damaged. ECT was shown to be an efficient therapy for treating tumors of the tongue, and it is expected to be suitable for the treatment of human oral cancers as soon as problems related to ECT damage of normal tissue are overcome.