Objective: The ultimate goal of this research is determining of depression prevalence and effective factors among boys of pre university level in Kazeron city.

Materials & Methods: The present research is an analytical - descriptive and cross sectional study, which was done in February 2001. In order to achieve the goal, 240 pre university boys were selected through random classified sampling and the data gathered by questionnaires and Zung depression scale.

Results: The results indicate that 42.9 percent of students suffered from depression. The rate of depression among the students is as follows: low depression 28.8%, medium depression 9.6% high depression 3.3%, and profound depression 1.3%. The statistical test, such as X² and X² for trend has been used. The results showed that there is a significant relationship between depression and family financial status, parents’ relations, talking about problems with others, anxiety about joining to military services, anxiety for entering to university, treatment of teachers and principals and educational level of mothers. With respect to the above mentioned variables and using a logistic regression model the following results achieved: Four variables had increasing effect on depression incidence: family financial status, parents’ relations, talking about problems with others and anxiety about going to military duty.

Conclusion: The advantage of the above model is not only to identify the effectiveness of the variables in depression but also by understanding of the students it is likely to prevent depression incidence.