We aimed to compare the (1) clinical outcomes including composite cardiovascular outcomes, cardiovascular death, and all-cause death, and (2) healthcare costs of using liraglutide and basal insulin as an initial treatment for patients with type 2 diabetes mellitus (T2DM) and high cardiovascular diseases (CVD) risk. This is a retrospective cohort study using Taiwan's Health and Welfare Database. A total of 1057 patients treated with liraglutide were identified and matched with 4600 patients treated with basal insulin. The liraglutide group had a lower risk of a composite CVD outcome (hazard ratio (HR) 0.65; 95% confidence interval (CI) 0.50-0.85; p < 0.01), all-cause mortality (HR 0.40; 95% CI 0.28-0.59; p < 0.0001), and nonfatal stroke (HR 0.54; 95% CI 0.34-0.87; p = 0.01). Compared to the basal insulin group, the liraglutide group had lower median per-patient-per-month (PPPM) inpatient, emergency room (ER), and total medical costs, but higher median PPPM outpatient, total pharmacy, and total costs (all p < 0.0001). In conclusion, compared to basal insulin, liraglutide was found to be associated with reduced risk of a composite CVD outcome, nonfatal stroke, and all-cause mortality among high CVD risk patients with T2DM. In addition, liraglutide users had lower inpatient, ER, and total medical costs, but they had higher outpatient and total pharmacy costs.