BACKGROUND: This study was conducted to evaluate the effect of an educational intervention on depression and quality of life (QoL) of patients with coronary artery bypass grafting (CABG) surgery. METHODS: This was a quasi-experimental study on 54 patients after CABG who were randomly divided into the test and control groups. To evaluate depression, Cardiac Depression Scale was used. Then a researcher-made questionnaire of Predisposing, Reinforcing, Enabling Causes in Educational Diagnosis and Evaluation (PROCEED) was used and finally the 36-item Short-Form Health Survey (SF-36) was employed. The intervention was done through 9 educational sessions, once a week, lasting 60-90 minutes based on PRECEDE model and it was followed-up for two months. RESULTS: After the educational intervention, the mean score of predisposing causes, enabling causes, reinforcing causes and self-care behaviors significantly increased in the test group compared to the control group (P < 0.001). There was a significant difference in mean score of depression between the two groups after the educational intervention (P < 0.001). In addition, there was a significant difference after the intervention in physical functioning (P = 0.04), mental problems related to QoL (P < 0.001) and generally, in psychological health (P = 0.04). CONCLUSION: The findings of this study confirmed the efficacy of PRECEDE educational model and its components (predisposing, enabling and reinforcing causes) and behavioral factors of it on improvement of psychological status and depression of the patients which finally increased QoL of patients after CABG. Keywords: Educational Intervention, Depression, Quality of Life, PRECEDE Model.