Dilated prosthetic grafts and anastomotic aneurysms are recognised as a long-term complication of aorto-ilio-femoral reconstruction. In the literature an incidence of 1-24% for anastomotic aneurysms and a mean dilatation of 85.7% for Dacron aortic prostheses is reported. In our own clinic the frequency of these complications was not known, and we started a follow-up study in order to establish: the mean dilatation of the prosthetic grafts, the actual incidence of anastomotic aneurysms and the relationship between these two. All patients (n = 61) who underwent aorto-ilio-femoral reconstruction between 1980 and 1985 were retrospectively studied. During the mean 8 years follow-up period 16 patients died (26%). Complete data were available from 36 patients, who underwent physical examination and ultrasonography. In the whole series the degree of dilatation varied from 0 to 44% with an average of 5.9% at the aortic level and 8.9% at the distal level. The diameters of 25 grafts remained unchanged, and the maximum dilatation observed was 44%. The incidence of anastomotic aneurysms in these patients was 13.8%. The anastomotic aneurysms were located at the following anatomical sites: aortic anastomoses 5.9%, iliac anastomoses 0 and 30.4% for the femoral anastomoses. There was no relationship between the dilated grafts and anastomotic aneurysms. In our clinic the degree of dilatation and the incidence of anastomotic aneurysms seems to be low, especially if we compare these results with the results reported by other investigators. None of the patients who underwent aorto-ilio-femoral reconstruction between 1980 and 1985 died or had to undergo emergency surgery because of graft failure or a ruptured anastomotic aneurysm.