Forty-four patients irradiated for metastatic or unresectable carcinoid tumors at Memorial Sloan-Kettering Cancer Center from 1950 to 1986 were studied. The response to radiation was analyzed at four sites: epidural space (11 pts), brain (8 pts), bone (8 pts), and abdominal (17 pts). Although survival was generally poor, substantial palliation was achieved in most cases. No patient with brain metastases had progression of intracranial disease after radiation therapy (median dose: 3300 cGy); all died of progression of systemic metastases (median survival: 4 months). Infield control following radiation therapy for epidural and osseous metastases was achieved in 77% and 78% of sites, respectively, with median doses of 3000 cGy and 4000 cGy. Median survival for epidural and bone metastases was 11 and 13 months, respectively. In-field control was obtained in 62% of patients with intraabdominal disease (median dose: 2700 cGy). Among the subset of seven patients who were irradiated at ten sites of unresectable abdominal (non-hepatic) disease, the median survival was 23 months with 80% achieving a complete or partial response and 50% maintaining permanent in-field control. No dose-response relationship was demonstrated. Radiation therapy can achieve local control and symptomatic palliation in most patients with metastatic carcinoid tumors. Our current recommendation would be to treat non-hepatic sites with 4500-5000 cGy in 4-5 weeks. More rapid fractionation schemes could be used for patients with limited life expectancies.