Neuroscience is revealing how the brains of individuals with Attention Deficit Hyperactivity Disorder (ADHD) function, and advances in medicine are leading to treatments. This study investigated preservice teachers' knowledge and beliefs about students with ADHD. The majority of preservice teachers knew someone with ADHD, which, along with courses taken and the media, allowed them to understand ADHD's signs, symptoms, and challenges. However, in general their responses showed a lack of understanding. The authors conclude that preservice teachers need information embedded in their coursework and mentors who understand know how to work with students with ADHD.