Aspirin is used mainly to prevent arterial events in patients with arteriopathy. Myocardial infarction and cerebrovascular events have been described after recent aspirin withdrawal. Experimental data suggest rebound platelet activity after aspirin discontinuation. Among a retrospective cohort of 181 patients admitted for acute lower limb ischemia for 4 yr, we studied 11 patients who had recently stopped taking aspirin. Aspirin was administered for vascular event prevention. The median duration of aspirin treatment without vascular events was 12 mo (range, 6-60 mo). The median time between aspirin withdrawal and lower limb ischemia was 23 days (range, 7-60 days). Four of the 11 patients stopped aspirin before a surgical procedure, without any substitution. In five patients, a recent diagnosis of neoplasia was observed. This study should alert clinicians to the risk of discontinuing chronic aspirin therapy in patients with severe peripheral vascular disease.