BACKGROUND: Achievement of diabetes care goals is suboptimal globally. Diabetes-focused quality improvement (QI) is effective but remains untested in South Asia. OBJECTIVE: To compare the effect of a multicomponent QI strategy versus usual care on cardiometabolic profiles in patients with poorly controlled diabetes. DESIGN: Parallel, open-label, pragmatic randomized, controlled trial. (ClinicalTrials.gov: NCT01212328). SETTING: Diabetes clinics in India and Pakistan. PATIENTS: 1146 patients (575 in the intervention group and 571 in the usual care group) with type 2 diabetes and poor cardiometabolic profiles (glycated hemoglobin [HbA1c] level >=8\% plus systolic blood pressure [BP] >=140 mm Hg and/or low-density lipoprotein cholesterol [LDLc] level >=130 mg/dL). INTERVENTION: Multicomponent QI strategy comprising nonphysician care coordinators and decision-support electronic health records. MEASUREMENTS: Proportions achieving HbA1c level less than 7\% plus BP less than 130/80 mm Hg and/or LDLc level less than 100 mg/dL (primary outcome); mean risk factor reductions, health-related quality of life (HRQL), and treatment satisfaction (secondary outcomes). RESULTS: Baseline characteristics were similar between groups. Median diabetes duration was 7.0 years; 6.8\% and 39.4\% of participants had preexisting cardiovascular and microvascular disease, respectively; mean HbA1c level was 9.9\%; mean BP was 143.3/81.7 mm Hg; and mean LDLc level was 122.4 mg/dL. Over a median of 28 months, a greater percentage of intervention participants achieved the primary outcome (18.2\% vs. 8.1\%; relative risk, 2.24 [95\% CI, 1.71 to 2.92]). Compared with usual care, intervention participants achieved larger reductions in HbA1c level (-0.50\% [CI, -0.69\% to -0.32\%]), systolic BP (-4.04 mm Hg [CI, -5.85 to -2.22 mm Hg]), diastolic BP (-2.03 mm Hg [CI, -3.00 to -1.05 mm Hg]), and LDLc level (-7.86 mg/dL [CI, -10.90 to -4.81 mg/dL]) and reported higher HRQL and treatment satisfaction. LIMITATION: Findings were confined to urban specialist diabetes clinics. CONCLUSION: Multicomponent QI improves achievement of diabetes care goals, even in resource-challenged clinics. PRIMARY FUNDING SOURCE: National Heart, Lung, and Blood Institute and UnitedHealth Group.