We evaluated the method of active specific intralymphatic immunization to treat cancer in 32 patients with various tumor types as part of a broad-based phase I-II evaluation and describe the results of 3 sequential series. In series 1, the patients (n = 13) received 2 or more injections of autologous, cryopreserved, irradiated tumor cells directly into the lymphatic system through the cannulation of a dorsal pedal lymphatic channel. In series 2, the patients (n = 7) received low-dose cyclophosphamide, 300 mg per m2, 3 days before the autologous cell vaccine was administered. Series 3 (12 patients) was similar to series 2 except that the tumor cells were treated with cholesteryl hemisuccinate immediately before irradiation. Patients received from 2 to 6 injections of cells, depending on availability, at 2-week intervals. In all, 91 treatments are evaluated in this study. Clinical responses occurred in 7 of the 32 patients and were seen in all 3 series with about the same frequency. These responses occurred in cases of melanoma, lung cancer, colon cancer, and sarcoma. Regressions occurred in both visceral and subcutaneous sites. There was little toxicity, the chief side effect being local discomfort or inflammation. This experience indicates that active specific intralymphatic immunotherapy is safe, produces antitumor effects, and requires more investigation to increase the frequency and duration of observable tumor regression.