AbstractAimsTo investigate the effectiveness, safety, optimal starting dose, optimal maintenance dose range, and target fasting plasma glucose of five basal insulins in insulin‐naïve patients with type 2 diabetes mellitus.MethodsMEDLINE, EMBASE, Web of Science, and the Cochrane Library were searched from January 2000 to February 2022. The Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA) guidelines were followed and the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) approach was adopted. The registration ID is CRD42022319078 in PROSPERO.ResultsAmong 11 163 citations retrieved, 35 publications met the planned criteria. From meta‐analyses and network meta‐analyses, we found that when injecting basal insulin regimens at bedtime, the optimal choice in order of most to least effective might be glargine U‐300 or degludec U‐100, glargine U‐100 or detemir, followed by neutral protamine hagedorn (NPH). Injecting glargine U‐100 in the morning may be more effective (ie, more patients archiving glycated hemoglobin < 7.0%) and lead to fewer hypoglycemic events than injecting it at bedtime. The optimal starting dose for the initiation of any basal insulins can be 0.10–0.20 U/kg/day. There is no eligible evidence to investigate the optimal maintenance dose for basal insulins.ConclusionsThe five basal insulins are effective for the target population. Glargine U‐300, degludec U‐100, glargine U‐100, and detemir lead to fewer hypoglycemic events than NPH without compromising glycemic control.