The present study investigated Florida teachers' perceptions of students with ADHD in the K-5 inclusive classroom settings. Attention deficit and hyperactivity disorder affects about 3-5% of American school-aged children. Participants (n = 48) were conveniently selected from 10 Florida public elementary schools. Participants completed the knowledge of attention deficit disorders scale (KADDS), which consists of three subscales: symptoms/diagnosis of ADHD (9 items), general information of the nature, causes, and impact of ADHD (15 items), and treatment of ADHD (12 items). An eight-item demographic questionnaire was also used. Teachers reported having more knowledge in the area of symptoms/diagnosis of ADHD when compared to the general information of the nature, causes, impact of ADHD, and treatment of ADHD. Data showed there was a positive relationship between the subscales: symptoms/diagnosis of ADHD, general information of the nature, causes and impact of ADHD, and treatment of ADHD. This study also found that teachers who engaged in self-study specific to the treatment of ADHD and general information about the disorder performed better than those not receiving any ADHD professional development at their school. Training for teachers regarding ADHD was crucial to better prepare them to assist students with ADHD. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]