This research is a semi-experimental study (pretest-posttest and follow-up design with a nonequivalent control group). To this end, a sample size of 30 secondary school male students (first period) was selected through convenience sampling and voluntarily from the statistical population of 10133 male students studying in District 1 of Mashhad. For data collection, Olweus Bully Questionnaire, Garnefski Cognitive Emotion Regulation Questionnaire and Social Adjustment Scale (SAS) were applied. The data was analyzed using SPSS software and based on variance analysis test with repeated measures, Hine-Feldet post hoc test and also the paired testof Bonferroni multiple comparisons. The results of this research demonstrated that behavioral parent training has had a significant impact on bullying, emotional regulation and social adjustment of students (P= 0.000).