Attention deficit hyperactivity disorder (ADHD) is one of the most common psychological disorders of childhood. Methylphenidate is highly effective in the treatment of ADHD. This study aimed to determine the effectiveness of combined Parent behavioral management training (PBMT) and medication treatment (Methylphenidate) in reducing ADHD symptoms in 6-12-year-old children, using randomized sampling. A total of 50 children with ADHD were assigned into two groups: an experimental group of PBMT and a control group of medication treatment (Methylphenidate) without other interventions. Conners’ Parent Rating Scale (CPRS-48) was employed before and after interventions to determine the effects. Descriptive Statistics method (consisting of Mean and Standard deviation) and Statistical inference method, (including t-test and Leveneʹs Test) were used for data analysis. Findings revealed that the combined behavioral intervention of PBMT and methylphenidate treatment is more effective in reduction of ADHD in children. The difference of means between pre-test and post-test of CPRS in the experimental group was equal to 10.77, and it was equal to 1.88 in the control group. In addition, PBMT was more effective in the case of younger parents (P<0.025). However, parents’ education level did not affect the behavioral intervention (P<0.025).The findings suggest that combined intervention of PBMT and methylphenidate is effective in reducing the symptoms of ADHD in children.