AIMS:We evaluated a theoretically-derived family-oriented intervention aimed to improve self-efficacy, self-management, glycemic control and quality of life in individuals living with Type 2 diabetes in Thailand. METHODS:In a single-blinded randomized controlled trial, 140 volunteer individuals with Type 2 diabetes, recruited from a diabetes clinic in rural Thailand, were randomly allocated to intervention and control arms. Those in the intervention arm received routine care plus a family-oriented program that included education classes, group discussions, a home visit, and a telephone follow-up while the control arm only received routine care. Improvement in outcomes over time (baseline, Week 3, and Week 13 following intervention) was evaluated using Generalized Estimating Equations multivariable analyses. RESULTS:Except for age, no between-group significant differences were observed in all other baseline characteristics. Diabetes self-efficacy, self-management, and quality of life improved in the intervention arm but no improvement was observed in the controls. In the risk-adjusted multivariable models, compared to the controls, the intervention arm had significantly better self-efficacy, self-management, outcome expectations, and diabetes knowledge (p<0.001, in each). Participation in the intervention increased the diabetes self-management score by 14.3 points (β=14.3, (95% CI 10.7-17.9), p<0.001). Self-management was better in leaner patients and in females. No between-group differences were seen in quality of life or glycemic control, however, in the risk-adjusted multivariable models, higher self-management scores were associated with significantly decreased HbA1c levels (p<0.001) and improved patient quality of life (p<0.05) (irrespective of group membership). CONCLUSIONS:Our family-oriented program improved patients' self-efficacy and self-management, which in turn could decrease HbA1c levels.