OBJECTIVE- The purpose of this study was to determine whether implementation of a multicomponent organizational intervention can produce significant change in diabetes care and outcomes in community primary care practices. RESEARCH DESIGN AND METHODS- This was a group-randomized, controlled clinical trial evaluating the practical effectiveness of a multicomponent intervention (TRANSLATE) in 24 practices. The intervention included implementation of an electronic diabetes registry, visit reminders, and patient-specific physician alerts. A site coordinator facilitated previsit planning and a monthly review of performance with a local physician champion. The principle outcomes were the percentage of patients achieving target values for the composite of systolic blood pressure (SBP) < 130 mmHg, LDL cholesterol <100 mg/dl, and A1C <7.0% at baseline and 12 months. Six process measures were also followed. RESULTS- Over 24 months, 69,965 visits from 8,405 adult patients with type 2 diabetes were recorded from 238 health care providers in 24 practices from 17 health systems. Diabetes process measures increased significantly more in intervention than in control practices, giving net increases as follows: foot examinations 35.0% (P < 0.0.001); annual eye examinations 25.9% (P < 0.001); renal testing 28.5% (P < 0.001); A1C testing 8.1%(P < 0.001); blood pressure monitoring 3.5% (P = 0.05); and LDL testing 8.6% (P < 0.001). Mean A1C adjusted forage, sex, and comorbidity decreased significantly in intervention practices (P < 0.02). At 12 months, intervention practices had significantly greater improvement in achieving recommended clinical values for SBP, A1C, and LDL than control clinics (P = 0.002). CONCLUSIONS- Introduction of a multicomponent organizational intervention in the primary care setting significantly increases the percentage of type 2 diabetic patients achieving recommended clinical outcomes.