Objective: To assess effects of the DPP-4 inhibitor sitagliptin in East Asian people with T2D in the Republic of Korea, Hong Kong or Taiwan (RoK-HK-T). Methods: Data from patients in randomized, placebo-controlled studies evaluating sitagliptin 100mg/qd as monotherapy or in combination with other AHAs (including sulfonylureas and insulin) in Korea (n = 183), Hong Kong (n = 139) or Taiwan (n = 60) were pooled. Change from baseline A1C at treatment Week 12 was assessed using an ANCOVA model with treatment, study, and baseline A1C terms. Missing A1C values were imputed using LOCF. Data collected following initiation of rescue medication were excluded. Results: Approximately 59% of patients were male, 89% were < 65 years old and 70% were on combination AHA therapy. Continuous baseline characteristics were generally balanced between treatments (mean A1C = 8.6%, age = 53.1 yrs, BMI = 25.5 kg/m2, duration T2D = 7.0 yrs; median HOMA-β = 21.2, HOMA-IR = 2.9). After 12 weeks of treatment, LS mean (95% CI) changes from baseline in A1C were -1.05% (-1.19, -0.92) and -0.06% (-0.21, 0.09) in the sitagliptin and placebo groups, respectively (between-group difference = -0.99% (-1.18, -0.81), p < 0.001). Similar changes in A1C occurred in subgroups with baseline A1C < and ≥ 8.5%. The percentages of participants with A1C < 6.5% / < 7.0% were 12.7%/29.5% (sitagliptin) and, 1.9%/3.1% (placebo) (between-group difference p < 0.001 for both targets). Through treatment Week 12, the incidences of any, serious, or serious drug-related AEs were similar in the treatment groups. The incidences of drug-related AEs were 9.8% and 5.4% in the sitagliptin and placebo groups, respectively, an imbalance primarily due to differences in the incidence of hypoglycemia. The incidences of any hypoglycemia (in studies not including sulfonylureas or insulin) were 1.2% and 0.8% in the sitagliptin and placebo groups, respectively. Conclusion: Sitagliptin 100 mg/qd was efficacious and generally well tolerated in patients treated in RoK-HK-T. Compared with data from global populations, these results may better represent efficacy in these patients.