This study aimed to assess the relation between attention deficit hyperactivity disorder among school age children and parent's stress and sense of competence. Design: A descriptive correlational research design was utilized in this study. The study sample included one hundred parents having children with ADHD. The study was conducted at the children and adolescents outpatient clinic in Minia hospital for psychiatric health and addiction treatment. Four tools were utilized to measure the variables of the study included; child's and parents socio-demographic data, parent disruptive behavior disorder (DBD) Rating Scale, parenting stress index scale, and parent sense of competency scale (PSOC). Results: it was found that more than three quarters of the children had combined type of ADHD. More than two thirds of parents had high level of stress & the majority of the parents were not competent. Conclusion: There were highly significant positive correlations between total ADHD and total parent's stress (p=.007) & there were highly significant negative correlations between parents sense of competence and total parent's stress. Recommendations: Counseling clinics for parents of ADHD children are needed to; ensure an effective parents response to the needs of ADHD children, increase awareness, coping, competence and to decrease parent's stress.