Previous studies recommend additional research to investigate teacher knowledge of ADHD. Additionally, we know little about the specific nature of training teachers receive on ADHD. The limited research is concerning given that ADHD is increasing. This nonexperimental descriptive and comparative quantitative study assessed ADHD knowledge among elementary public school teachers in a mid-Atlantic public school district. The Knowledge of Attention Deficit Disorder Scale (KADDS) instrument was used to specifically examine three topics. One, how knowledgeable are teachers about the associated features, symptoms and diagnosis, and treatment of ADHD? Two, what are the differences in teachers' knowledge of ADHD in terms of associated features, symptoms and diagnosis, and treatment? Three, to what extent are demographic variables (e.g., age, gender, years teaching, level of education, and race) and knowledge and experience variables (degree program training, district training, school training, number of students with ADHD taught in the last 2 years, and self-study) associated with KADDS scores. Results indicated that educators have insufficient knowledge of ADHD. Educators' knowledge was strongest around symptoms and diagnosis and weakest in associated features. While other demographic and survey data showed significant correlation with KADDS scores, three stood out as the most consistent and showed the highest level of correlation: the number of students with ADHD taught in the last 2 years, the educator's opinion of how well their degree program prepared them to support students with ADHD, and the number of articles educators read about ADHD outside of university- or district-offered training (i.e., self-study). [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]