A case of primary non-Hodgkin's lymphoma of the terminal ileum with enterovesical fistula is reported. A 50-year-old Malay man presented with haematuria, dysuria and per-rectal bleeding. Intravenous urogram, double contrast enema and an MDP bone scintigram showed a fistulous communication between the bladder and distal ileum. At laparotomy, a large tumour attaching the terminal ileum to the dome of the bladder was found. Histopathological examination of resected small bowel revealed a diffuse histiocytic non-Hodgkin's lymphoma of the small bowel. The bladder mucosa was shown to be normal.