Ten patients with carcinoma of the anorectum were treated with a combination of external irradiation and after-loading interstitial 192Ir implant, which seems to be effective in controlling relatively small cancers of the anorectum and providing effective palliation of extensive lesions. Five of the 10 patients remain free of tumor after a minimum follow-up of 15 months. Four of the 10 were treated with one interstitial implant and 4,000--5,000 rads of external irradiation and 6 were treated with the same amount of irradiation and two implants. When two implants were used, complications were minimal.