Background: ADHD is one of the most common childhood psychiatric disorders, not only in Egypt but also in the world. The aim was to assess the effectiveness of an educational intervention on improving the elementary teachers‟ knowledge, attitudes and sense of self efficacy toward ADHD children. Methods A quasi-experimental, quantitative, (pre/ post one group) research design was used with 100 elementary teachers recruited conveniently from two schools located at Shebin Elkom city ,affiliated to Ministry of Education, Menoufyia Governorate, Egypt. Data were collected by using 3 main tools which are The KADDS scale, The teacher attitude towards inclusion scale (TAIS) ,and Teacher Efficacy Beliefs Scale (TEBS) for instructing and managing students with behavioral difficulties The results revealed that, the majority( 95% &96%) of studied subjects were Bachelor degree of education .and their mean age was(40.99±9.73). There was a highly statistical significant difference between pre and post interventions of knowledge of Attention Deficit disorders (KADDS), teacher self-efficacy beliefs at p-value < 0.000. While, there was no significant difference between pre and post teachers‟ attitudes of including ADHD students in their regular classes. Conclusion: the current study demonstrated that educational interventions can increase elementary school teachers‟ ADHD knowledge and self-efficacy. Whereas improving attitudes was little with no significant difference between pre/post assessment, our findings suggest that a brief professional educational intervention can be utilized to greatly increase teachers‟ ADHD knowledge, providing a costeffective, practical solution to address this well-evidenced gap in teachers‟ training and knowledge about the disorder. Therefore, it is recommended that there is an urgent need to ensure that pre-service and in-service elementary school teachers have a sound knowledge of ADHD and maintain favorable attitudes toward teaching children with ADHD.