Attention deficit hyperactivity disorder is one of the most prevalent behavioral disorders affecting children and adolescent worldwide. It causes a grave problem to child, teacher and family. The study aimed to evaluate the effect of educational program about Attention Deficit Hyper Activity Disorder on primary schools teacher's knowledge and skill. This study was conducted at two governmental primary schools at Elgharbia Governorates (one urban and another rural), the subject of the study were 50 primary school teachers. This study followed a quasi-experimental design. Two tools were used for the data collection, Tool 1 include : part a: Socio-demographic data, : part b: Knowledge of Attention Deficit hyper activity Disorders Scale (KADDS) to assess teachers' knowledge about ADHD, Tool 2 include : Teacher Intervention Survey to determine teachers skills regarding interventions that a teacher can use with students with a DHD.. The study program included 4 sessions for six months. The designed educational program helped teachers through providing efficient knowledge and skill regarding ADHD. The results revealed that the designed program had an effective impact on teachers' knowledge and skill regarding ADHD as there was a statistically significant difference between total score of knowledge and skill before implementing the program, immediately after and at follow up .The study concluded that educational program about ADHD can improve level of teacher's knowledge and skills about ADHD. According to these results, the researcher recommended that teachers should be offered in-service training in ADHD, as well as behavioral management and academic interventions (curriculum adaptations) regarding ADHD.