Given that adolescents with thalassemia major have low life expectancy and spiritual health due to disease, treatment and complications, and given that religious care is an easy, uncomplicated and inexpensive method, this study was conducted with the aim of determining the effect of religious care education.The present quasi-experimental study was performed on34 teenagers referring to Ali Asghar Hospital. Research tools included questionnaires:demographic characteristics, Schneider’s life expectancy, and Paloutzian and Ellison’s spiritual health scale.the intervention group took part in six educational sessions of 40-60-minute, religious care. The results showed that the two groups had no statistical difference in terms of the total score of life expectancy and the average score of spiritual health before the intervention, but the comparison of the average score of life expectancy and the average score of spiritual health after the intervention showed a statistically significant difference between these two groups.Considering the importance of life expectancy and spiritual health in the recovery and follow-up of patients from the treatment regimen and treatment follow-up, spiritual and religious care education, which is followed by the improvement of spiritual health and life expectancy, can be very beneficial for adolescents with thalassemia major.