Teachers play a crucial role in the diagnosis and management of children with attention deficit hyperactivity disorder (ADHD). In the United Arab Emirates (UAE), teachers' understanding of this condition has not been evaluated so far. Our study included teachers (n = 394) from 25 randomly selected primary schools in Dubai with the purpose of evaluating levels of knowledge about ADHD. Participants were asked to complete the "Knowledge of Attention Deficit Disorder Scale" (KADDS). On average, teachers showed knowledge on about half of the items in the questionnaire (48.2%), with the highest level of knowledge reported on the subscale related to symptoms/diagnosis (65.7%). We identified specific characteristics of ADHD where teachers' understanding could be improved through training programs. This is important since awareness about the characteristics of ADHD supports the early detection of the disorder and also helps the learning environment for children with the condition.