To test the hypothesis of a myofascial component in intermittent claudication, 56 male patients were studied. Calf blood flow, at rest and during postischemic and postexercise hyperemia, presence of trigger areas, and exercise tolerance were evaluated and compared. The results can be summarized as follows: The exercise tolerance is reduced when trigger areas are present in the calf muscles, and the more severe the trigger areas, the lower is the exercise tolerance. Trigger areas are more severe when the hyperemic flow is more reduced. The peak flow of reactive hyperemia is also correlated to work load. Pain in intermittent claudication is a complex phenomenon. According to the aforesaid results, the severity of limb ischemia and the presence of trigger areas in the calf appear to be the major factors. Besides the two reasons already known, a third is suggested to explain calf claudication: the elective location of trigger points in the gastrocnemius muscle.