The rationale for freezing carcinoma adjunctively with chemotherapy is synthesized from published data on tumor cytokinetics, regional chemotherapy, cryopathology, and the microvascular hemodynamics of proliferating tumors. Acute cryolesions in the dog’s tongue, arterially infused with methylene blue solution demonstrated early central ischemia, increasing porosity of marginal circulation and extravascular trapping of dye for 5 h. The dog intestine tolerated transmural cryonecrosis without perforation. 27 patients with cancer of the oral cavity received Methotrexate arterial infusion with cryosurgery without complications since May 1969. Bleeding with later surgery occurred in 2 patients, and a possible relationship to cryosurgery is discusse