Depression is an increasingly prevalent mental health issue among students. Among all depression preventive factors, religious commitment as a deterrent for many mental disorders, especially depression, has attracted the attention of many researchers. However, the results of related studies about the effect of religious are controversial. Thus, the present study aimed to investigate the relationship between religious beliefs, adherence to ethical standards and Islamic rules with depression among students of Arak University of Medical Sciences. This cross-sectional study was conducted on 120 Medical students by using stratified random sampling. Zung depression self-assessment scale and researcher made questionnaire for assessing adherence to Islamic laws, beliefs and ethical standards were used to collect the data. Data analyzed using statistical software SPSS version 18 and descriptive statistics and Pearson correlation coefficient. The results showed there was a significant negative correlation (p<0.05) between depression and adherence to laws, beliefs and ethical standards of students. Religious promotion of students causes them to be less depressed and plays an important role in the prevention of mental disorders in their lives.