In the US Physicians' Health Study the early termination of the aspirin arm has provided the opportunity to test the hypothesis that low-dose aspirin (325 mg on alternate days) might affect the subsequent occurrence of peripheral arterial surgery. In the study, a randomised double-blind placebo-controlled trial among 22,071 healthy US male physicians aged 40-84, there were, during an average of 60.2 months of treatment and follow-up, 56 participants who underwent peripheral arterial surgery (20 aspirin, 36 placebo). The relative risk of peripheral artery surgery in the aspirin group was 0.54 (95% confidence intervals 0.30-0.95; p = 0.03). These data indicate that chronic administration of low-dose aspirin to apparently healthy men reduced the need for peripheral arterial surgery.