Peripheral arterial disease (PAD) patients are commonly classified on the basis of subjective evaluations of pain and fatigue. Surface electromyography (EMG) is an objective method for studying peripheral muscle fatigue. Fifteen patients with PAD and 15 healthy volunteers matched for age and sex were studied. Surface EMG was recorded over the medial gastrocnemius during 100 seconds at 60% of maximal effort. EMG traces were analyzed off-line to obtain the power spectrum. The median frequency was calculated in the first 30 seconds (T0) and between 70 and 100 seconds (T1). Significantly lower T1 values, compared with T0, were found in both the PAD and the control groups (p < .005; p < .05). T0 values were not different between group, whereas T1 values were significantly lower in PAD patients (p < .01). EMG frequency analysis can be considered an easy, painless method providing objective information on muscular performance and fatigue in PAD patients.