Introduction: Attention deficit hyperactivity disorder (ADHD) is the most common neurodevelopmental disorder diagnosed in childhood and it is characterized by chronic symptoms of inattention, impulsivity, and hyperactivity that lead to function impairment experienced in multiple daily activity. (Danielson & Melissa, 2016). ADHD is characterized by deficits of executive functions, and that a deficiency in the executive control of emotions is a necessary component of ADHD. According to this theory, the extent to which an individual with ADHD displays a deficiency in behavioral inhibition is the extent to which he or she will automatically display an equivalent degree of deficiency in emotional inhibition (Villemonteix et al., 2014).Methods: A descriptive (cross-sectional study) was conducted to assess Primary school teacher's knowledge about attention deficient hyperactivity disorder (ADHD) among student at primary school in Karbala city and find out the association between the teachers knowledge toward ADHA and their socio-demographic characteristics. The study started from the period of 27th October 2021 to the 20th of June 2022. A non-probability (convenience) sample of 85 teachers, were purposive. The questionnaire format was designed and composed of two parts: the first part includes two sections that deal with the teacher's socio-demographic characteristics, and source of information about ADHD whereas the second part teacher's knowledge domain, which involves (21 items). Results :The results of the present study indicated that the majority of studied teachers had low level of knowledge, which was no significant associated with (age of teachers, gender, level of education of teachers, Number of years of service).there was no significant association between Teachers' knowledge and attitudes toward child ADHD and their compliance, and recommended that it is necessary to increasing the public knowledge and awareness about the importance of ADHD by implementing educational programs which can be delivered through mass media, booklets, and primary health care centers staff.Concludes: Most of the study sample was female (76.5%),The overall assessment of teachers' knowledge is low about ADHD.