The present study was carried out to investigate the effectiveness of mindfulness-based stress reduction in depression reduction and blood sugar control in diabetic patients with Behavioral Inhibition type of personality. It was a quasi-experimental study with pretest/posttest design employing one experimental and one control group. The participants were 225 patients in Tehran. First, 30 patients with diabetes Type 2 were selected on the basis of interview and then randomly assigned to two experimental and control groups (n=15 in each group). Then, Wilson’s personality questionnaire and beck’s depression inventory were used to collect data. After conducting the pretest and measuring blood sugar level, the experimental group received an intervention in eight sessions of 120 minutes while the control group received no intervention. Finally, the posttest was administered to both groups. The results indicated that there was a significant difference between the results of the pretest and posttest, indicating that mindfulness-based training had a positive effect on the reduction of stress as well as reduction of blood sugar among patients with type 2 diabetes. Therefore, the mindfulness-based educational method can be used in clinics and healthcare centers to reduce stress and blood sugar levels among patients suffering from diabetes Type 2.