A retrospective analysis of 545 patients, operated on between 1970 and 1987 for a closed or ruptured infrarenal aneurysm of the abdominal aorta (AAA), revealed an incidence of 5.1% of unilateral leg amputations among them (20 above, 8 below the knee) during the Second World War. Patients in both groups (with or without amputation) had one or more arteriosclerotic risk factors, their frequency rising with increasing age. There were differences between the two groups in the frequency of certain morphological characteristics in the area of the bifurcation and the terminal aorta affecting the haemodynamics of these regions. Stenosis or occlusion of the ipsilateral iliac arteries may be a possible pathogenetic factor. A prospective study will be required to decide whether the coincidence between leg amputation and AAA is pathogenetic or accidental.