Since 1935 at the Hospital for Sick Children in Toronto, 13 cases of carcinoid have been seen as incidental findings in the appendix, but carcinoids of the rectum have never previously been reported in childhood. The authors report a child with a rectal duplication in which this tumour was found. The rationale for local resection of the duplication with its contained carcinoid is understood in the light of the principles for treatment of intestinal carcinoids in general and carcinoids of the rectum in particular. Two years after operation the child is well without signs of local or systemic recurrence.