SummaryAdministration of 5‐FU and198Au directly to regional lymphatics was utilized as an adjuvant to surgical operation in patients with potentially curable carcinomas of the colon and rectum. The five‐year survival rates in 107 patients receiving 5‐FU and 58 patients receiving198Au were compared with that in 136 patients treated by surgical resection alone.In 5‐FU‐treated patients, either with or without cancer metastatic to the regional lymph nodes, there was no improvement in survival over that in the control group. Similarly,198Au had no effect on the survival rate of patients without tumor cells in the regional nodes. However, 53 per cent of198Au‐treated patients with metastases to lymph nodes were alive after five years, compared with 24.4 per cent of the comparable control group.These results suggest that regional intralymphatic administration of Radiotherapeutic agents as an adjuvant to surgery offers some promise in the treatment of colorectal carcinoma and that continued evaluation is justified.