The purposes of this paper are study of effective level of mental health education program on reducing mental disorders. To this aim, 440 high school students at the pretest phase selected randomly with multi-stage sampling method among Tehran city high school students. Then, General Health Questionnaire (GHQ – 28) as a mental health and mental disorders screening instrument was administered on the students. The present study cutoff point is 23 with 79/2 and 0/91 as sensitivity and specificity respectively. Also, for determining reliability used Chronbach alpha that is obtained 0/86 coefficient that is statistically satisfactory. Given to the cutoff point (>23), the 80 (18/2%) student is scored above cutoff point that 22/2% and 12/6% were girls and boys students respectively. At the treatment phase for determining level of effective of mental health education program, two matched experimental group and control group according to dependent variable, age and gender were formed that experimental groups are exposed to mental health education program. At the posttest phase, after presenting treatment variable (mental health education program) to experimental groups versus non-presenting to control groups, both of groups was tested with GHQ – 28 again. The results has shown that the treatment promoted high school students mental health, in other words, it led to reduce anxiety and insomnia symptoms, social dysfunction symptoms and severe depression symptoms, nevertheless, it did not cause difference in terms of physical symptoms between experimental and control groups.