The present study was conducted to investigate the effectiveness of executive functions training on Social competence and aggression in children with sluggish cognitive tempo. The statistical population included elementary school children with sluggish cognitive tempo who referred to educational counseling centers in Mashhad in the academic year of 2021-2022. In this research, 35 children with sluggish cognitive tempo were selected by purposeful sampling and randomly assigned to experimental and control groups (18 children in the experimental group and 17 children in the control group). Children in the experimental group received the executive functions during eight weeks in eight 75-minute sessions. Sluggish Cognitive Tempo Questionnaire (SCTQ), Social Competence Questionnaire (SCQ), Childrend Aggression Questionnaire (CAQ) were used in the present study. The data were analyzed through mixed ANOVA via SPSS23 software. The results showed that executive functions training has significant effect on the Social competence (p<0001, Eta=0.61, F=51.32) and aggression (p<0001, Eta= 0.64, F=60.75) in the children with sluggish cognitive tempo. According to the findings of the present study it can be concluded that executive functions training can be used as an efficient method to improve Social competence and decrease aggression in children with sluggish cognitive tempo through employing techniques such as increasing attention, concentration and accurace, organizing activities, avoiding response, controlling impulsivity and planning training.