---

Abstract
Background. Self-care behaviors in cardiac patients are one of the essential factors in their treatments. The failure to apply proper self-care behaviors reduces their recovery and imposes high costs on the health care system.
Aim. This study aimed for design and psychometric measurement of the questionnaire on attitude, knowledge and utilization of self-care for patients undergoing coronary artery bypass graft surgery based on Waltz model
Method. In this methodological study, the following four steps were conducted for design and psychometric measurement of the questionnaire: 1) defining the theoretical and practical self-care concept for patients undergoing coronary artery bypass graft surgery in the domains of physical activity, sexual activity, social activity, mental state, and smoking; 2) designing the items of the questionnaire using other instruments which are being used in heart diseases; 3) determining the face validity (the assessment of facility, difficulty, and ambiguity of the items and their importance for patients) and content validity of the questionnaire (the assessment of appropriateness and necessity of items by experts opinions and measuring CVR and CVI; 4) the internal consistency of the questionnaire was evaluated by determining the Cranach's alpha coefficient.
Findings. The first version of this questionnaire was produced with 56 items, of which 15 items were deleted during the process of validity and reliability confirmation. The final version of the questionnaire was provided with 41 items in three domains; knowledge domain with 14 items, attitude domain with 7 items and utilization domain with 20 items. The results of the psychometric procedure for the questionnaire was the content validity index of 0.99, the content validity ratio of 0.96 and the internal consistency of the questionnaire with Cronbach's alpha coefficient of 0.7 representing appropriate validity and reliability of the questionnaire.
Conclusion. This 41-item questionnaire can be utilized in the assessment process of these patients. Measuring construct validity is recommended for the validity of the domains of the present questionnaire.