PURPOSE: The purpose of the Families United/Familias Unidas study was to evaluate the feasibility and efficacy of group office visits on reducing diabetes risk in a multiethnic, primary care population. METHODS: Adults, ages 18 to 70 years, with any diabetes risk factor were recruited to attend 12 group office visits over 6 months. Each participant identified 1 support person, age 14 to 70 years, to accompany them. Data were collected at baseline, postintervention, 6 months, and 12 months. Primary outcome measures were reduction in the total number of predefined, modifiable risk factors (ie, body mass index ≥25 kg/m; waist circumference ≥88 cm [women], ≥102 cm [men]; blood pressure ≥140/90 mm Hg; hemoglobin A1C ≥5.7%; fasting insulin ≥15 μU/mL; glycemic index ≥52.5% [women], ≥53.4% [men]; and physical activity <150 min/wk). RESULTS: Thirty-nine participants/supporters completed the intervention (mean age 47.8 ± 12.3 years, 69.2% female, 61.5% white, 35.9% Latino). Risk reduction analysis included only participants/supporters who remained paired at the interventionʼs end (n = 36). At baseline, primary participants (n = 18) had an average of 4.8 ± 1.6 (standard error) predefined risk factors; supporters (n = 18), 4.1 ± 1.4. Primary participantsʼ risk factors decreased approximately 15% immediately after the 6-month intervention (absolute reduction of 1.1 risk factors) and increased to ~20% reduction 1 year postintervention (absolute reduction of 1.4 risk factors). Risk reduction was primarily due to decreases in dietary glycemic index and fasting insulin levels. CONCLUSIONS: Group visits provide an innovative and potentially efficacious model of diabetes prevention in multiethnic patients with heterogeneous risk factors.