Transcatheter intra-arterial therapy for the cancer patient encompasses infusion of chemotherapy and embolization. Intra-arterial infusion of chemotherapeutic agents has been resurrected because of the availability of new drugs, combinations of drugs, and the capability of percutaneous selective catheter placement. Intra-arterial infusion has been effective in patients with carcinomas of the liver, bladder, prostate, uterus, ovary, and lung and in bone and soft tissue sarcomas, melanomas, and tumors of the brain. Embolization of the arterial supply, creating ischemia of the neoplasm, has been employed in the therapeutic management of patients with primary and secondary neoplasms of the liver, kidney, and bone. The median survival of 100 patients with neoplasms of the liver from the time of hepatic artery embolization was 11.5 months. In 100 patients with pulmonary metastases from carcinoma of the kidney, 28 experienced a response to renal artery embolization, a therapeutic delay of 4 to 7 days, nephrectomy, and Depo-Provera (medroxyprogesterone). Seven of 12 patients with giant cell tumor of the pelvis and lumbar spine responded to arterial embolization after all other therapy failed. Chemoembolization, the combination of arterial infusion of chemotherapy and embolization, can be accomplished by the use of microencapsulated agents, liposomes, and particulate emboli with drugs. This approach integrates the advantages of infusion and occlusion, and has considerable potential. Intra-arterial immunotherapy has been initiated with bacillus Calmette-Guerin (BCG) administration into renal neoplasms in patients with metastatic disease.