CT was performed on 80 patients referred for staging and treatment of histologically verified midgut carcinoid tumours. In 17 cases (21%) CT was normal in spite of biochemical signs of tumour (increased U-5-HIAA). The most common finding was liver metastases in 54/80 (68%) of patients. Mesenteric metastases, usually as a soft tissue mass at the mesenteric root, were found in 17/80 (21%). Retroperitoneal adenopathy was found in 19/80 (24%). During a follow-up time of 3 months to 10 years (median 3 years) 445 additional CT examinations were performed on 77 patients. In 39 of these, progressive disease (new lesions) was found after a median time of 15 months (range 3 months-6.5 years). CT is poor in detecting primary carcinoid tumours but helpful in evaluating the extent of tumour spread before surgical exploration and during follow-up once the diagnosis has been established.