Family interventions may improve glycemic control among diabetic patients To evaluate the association of glycemic control with family support and level of knowledge in patients with type 2 diabetes. Patients with type 2 diabetes completed a demographic survey. Glycosylated hemoglobin (HbA1c) was determined and glycemic control was defined as a value < 6,5%. Two validated instruments were applied to evaluate family support, stratifying it in three categories (low, medium and high) and the level of knowledge about diabetes. We studied 81 patients aged 32 to 65 years (53 females). Thirty six percent had an adequate glycemic control. Participants with a medium family support had three times greater risk of having an uncontrolled blood glucose than subjects with high family support. No significant association was found between the level of knowledge and glycemic control. Family support but not knowledge about the disease is associated with a better glycemic control of patients with type 2 diabetes.