We evaluated the role of statins in delaying insulin use and diabetes-related diseases in Asian patients with type 2 diabetes mellitus (T2DM) because statins can cause new-onset diabetes.We used data from the Longitudinal Health Insurance Database in this retrospective cohort study. The 12,470 T2DM patients were categorized into 2 cohorts: a statin cohort comprising 2545 patients who received statin therapy for at least 6 months (180 days) before the index date and a nonstatin cohort comprising 9925 patients who did not receive statin therapy. The control-to-case ratio was set at approximately 4:1. Univariable and multivariable Cox proportional hazards regression analyses were performed to evaluate the risk of diabetes-related events and insulin use on receiving statin treatment.Patients in the statin cohort had a 48% lower risk of diabetes-related coma than those in the nonstatin cohort (95% confidence interval = 0.29-0.92). Patients with >730 days of statin therapy had a significantly lower risk of insulin use, diabetes-related disorders of the eye and neurons, and peripheral circulatory disorders. Compared with patients in the nonstatin cohort, the risk of insulin use, diabetes-related coma, and diabetes-related disorders of the eye and neurons was lower in patients on a cumulative defined daily dose (cDDD) of statins for >475 days.These results suggest that longer duration of statin use and higher cDDD of statins can delay insulin use in Asian patients with T2DM.