A case of ischaemic ileal perforation associated with a macroscopically unapparent ileal carcinoid is described. The mesenteric vessels were non-pulsatile at operation but were anatomically patent when examined by the pathologist. The characteristic elastic perivascular sclerosis of mesenteric vessels, which probably caused a functional vascular obstruction, was only discovered after the histological sections were reviewed. The true incidence of this rare condition may be higher than previously suspected because the perivascular sclerosis can easily be overlooked. Awareness of the association between carcinoid tumour and mesenteric ischaemia may lead to early surgery and an improved outcome.