Long-acting basal insulins are used for the management of both type 1 and type 2 diabetes mellitus. Long-acting basal insulins were developed utilizing recombinant DNA technology and have been available since 2000 with the approval of insulin glargine U-100 followed by insulin detemir in 2005. In recent years, diabetes management has become more complex with the approval of insulin glargine U-300 and insulin degludec U-100 and U-200. Both insulin glargine U-300 and insulin degludec have been compared with insulin glargine U-100 and have demonstrated longer durations of action, as well as lower rates of hypoglycemia. This review discusses the Food and Drug Administration-approved long-acting insulins with a focus on recently approved agents and their efficacy and safety compared with the first long-acting basal insulins.