Diabetes education has largely been accepted in diabetes care. The effect of diabetes education on glycemic control and the components of education responsible for such an effect are uncertain. We performed a meta-analysis of randomized controlled trials of diabetes patient education published between 1990 and December 2000 to quantitatively assess and characterize the effect of patient education on glycated hemoglobin (HbA(1c)). Additionally, we used meta-regression to analyze which variables within an education intervention that best explained variance in glycemic control. Twenty-eight educational interventions (n=2439) were included in the analysis. The net glycemic change was 0.320% lower in the intervention group than in the control group. Meta-regression revealed that interventions which included a face-to-face delivery, cognitive reframing teaching method, and exercise content were more likely to improve glycemic control. Those three areas collectively explained 44% of the variance in glycemic control. Current patient education interventions modestly improve glycemic control in adults with diabetes. We highlight three potential components of educational interventions that may predict an increased likelihood of success in ameliorating glycemic control.