Background Supervised exercise therapy (SET) is recommended as the primary treatment for patients with intermittent claudication (IC). However, there is concern regarding the safety of performing SET because IC patients are at risk for untoward cardiovascular events. The Dutch physical therapy guideline advocates cardiac exercise testing before SET, if indicated. Perceived uncertainties concerning safety may contribute to the underuse of SET in daily practice. The objective of this review was to analyze the safety of supervised exercise training in patients with IC. Methods Two authors independently studied clinical trials investigating SET. Data were obtained from MEDLINE, EMBASE, and The Cochrane Central Register of Controlled Trials. Complication rates were calculated and expressed as number of events per number of patient-hours. The usefulness of cardiac screening before SET was evaluated in a subanalysis. Results Our search strategy revealed 2703 abstracts. We selected 121 articles, of which 74 met the inclusion criteria. Studies represent 82,725 hours of training in 2876 IC patients. Eight adverse events were reported, six of cardiac and two of noncardiac origin, resulting in an all-cause complication rate of one event per 10,340 patient-hours. Conclusions SET can safely be prescribed in patients with IC because an exceedingly low all-cause complication rate was found. Routine cardiac screening before commencing SET is not required. Our results may diminish perceived uncertainties regarding safety and will possibly increase the use of SET in daily practice.