This study aimed to determine the effect of education intervention, based on social cognitive theory, on self-care behaviors in patients with type 2 diabetes.This study was conducted in descriptive and interventional stages. The effective factors and constructs of social cognitive theory were identified in a descriptive study (n = 320). After that, a quasi-experimental study was conducted to determine the effect of intervention on 120 diabetic patients whom were randomly assigned to experimental and control groups. The educational intervention was implemented in six 40 -minute sessions for the experimental group. The questionnaires were completed before, immediately after and three months after the intervention.The results of regression showed that emotional adaptation (P < 0.05), self-efficacy to overcome barriers (P < 0.05) and self-regulation (P < 0.05) could predict self-care. There was no significant difference between the experimental and control groups before the educational intervention, however, after the intervention, there was a significant difference in self-care (p < 0.001), knowledge (p < 0.001), outcome expectations (p < 0.001), outcome value (p < 0.001), self-efficacy (p < 0.001), self-efficacy to overcome barriers(P < 0.001) p), environment (p < 0.001), observational learning (P < 0.05), situational perception (p < 0.001), self-regulation (p < 0.001) and emotional adaptation (p < 0.001)) in the intervention group.The results of this study showed that intervention, based on social cognitive model, has a positive effect on diabetes self-care in the patients. Emotional adaptation, self-efficacy to overcome barriers and self-regulation have the biggest impact on diabetes self-care.