Diabetes mellitus is one of the most common chronic metabolic diseases characterized by increased blood sugar and impaired insulin secretion or function. Aerobic exercise is recognized as one of the main pillars of diabetes management.The aim of this review is to investigate the effects of aerobic exercise on glycemic control, insulin sensitivity, and cardiovascular risk factors in patients with type 1 and type 2 diabetes.Methods: This study was conducted as a systematic review. Articles were searched for up to 2018 in PubMed, Scopus, Web of Science, SID, and Google Scholar databases. The keywords “Aerobic Exercise”, “Type 1 Diabetes”, “Type 2 Diabetes”, “Insulin Sensitivity”, and “Glycemic Control” were used.Articles were selected that evaluated the effect of aerobic exercise as the main intervention on blood sugar, insulin, lipid, inflammation, or aerobic capacity indices. Finally, 67 articles were selected and analyzed according to the inclusion criteria.Results: Evidence shows that regular aerobic exercise significantly improves HbA1c, increases insulin sensitivity, reduces insulin resistance, improves body composition, and reduces cardiovascular risk factors in both types of diabetes. In type 2 diabetes, a 0.5-0.8% reduction in HbA1c has been reported with regular aerobic exercise. In type 1 diabetes, aerobic exercise mainly improves cardiorespiratory fitness and reduces the risk of cardiovascular complications.Conclusion: Aerobic exercise, as an effective non-pharmacological intervention, plays a vital role in the management of type 1 and type 2 diabetes.It is recommended that diabetic patients engage in at least 150 minutes of moderate-to-vigorous intensity aerobic activity per week.