This systematic review examined the interrelationship between concomitant diabetes mellitus (DM) and peripheral arterial disease (PAD). The objective was to determine differences in the prevalence as well as in the outcomes in diabetic vs. non-diabetic PAD patients. The current review followed a study protocol that was published online in German in 2017. The search included societal practice guidelines, consensus statements, systematic reviews, meta-analyses, and observational studies published from 2007 to 2020 reporting symptomatic PAD and concomitant DM in patients undergoing invasive open-surgical and endovascular revascularizations. German and English literature has been considered. Eligibility criteria were verified by three independent reviewers. Disagreement was resolved by discussion involving a fourth reviewer. 580 articles were identified. After exclusion of non-eligible studies, 61 papers from 30 countries remained, respectively 850,072 patients. The included studies showed that PAD prevalence differed between diabetic vs. non-diabetic populations (20-50% vs. 10-26%), and further by age, gender, ethnicity, duration of existing diabetes, and geographic region. The included studies revealed worse outcomes regarding perioperative complications, amputation rate, and mortality rate in diabetic patients when compared to non-diabetic patients. In both groups, the amputation rates decreased during the research period. This review emphasizes an interrelationship between PAD and DM. To improve the outcomes, early detection of PAD in diabetic patients, and vice versa, should be recommended. The results of this systematic review may help to update societal practice guidelines.