Background: Multiple environmental factors have roles in producing anxiety. Individualized differences and environmental conditions can affect the anxiety level. So, hospital environment and especially cardiac surgery ward have a great importance because they can save the patient's life.

Material & Methods: The present study is a descriptive- analytical one which has been conducted upon studying the level of anxiety pre and post coronary artery bypass graft surgery in the hospitals of Tehran University of Medical Sciences and preparing an educational program for such patients, was the other goal of the study.

Study population consists of 150 patients under examination that at the time of the study have been voluntaries to coronary artery bypass graft surgery. The sample was studied 24 hours before and weeks after surgery. The sample was selected randomly and data collected through a questionnaire with two separate parts. For the purpose of data analysis, SPSS software was employed.

Results: The result of the study shows that the level of anxiety before coronary artery bypass graft have been more than the level of anxiety after  the operation. The difference between of the levels of anxiety have had significant relations with some of independent variables of the study such as sex, age, number of children and marital status, but there were not significant relations between occupation, educational level, non cardiac disease background, background of MI, non cardiac surgery background, the period of suffering from coronary disease background of hospitalization.

Conclusion: It seems that the men's ability to return to pre-operation socio-economic condition reduces their post operation anxiety. When people become older, they will be more fearful regarding the future's events but people older than 46 years old will obtain more life expectancy after surgery due to more extended familial relationship.

Married people experience less anxiety due to post operation, familial responsibilities and relief of cardiac symptoms. It can be concluded that anxiety reduction in these patients can result from cultural, socio-economic and demographic variables. Believes as cultural factors in the life have a great role in appearance and the level of anxiety.