Objectives The aim of this study was to investigate elementary school teachers’ knowledge and perception of attention-deficit/hyperactivity disorder (ADHD). Variables associated with the teacher’s tendency to recommend treatment to parents of the ADHD children were also evaluated. Methods A total of 73 elementary-school teachers completed a self-questionnaire regarding their demographic characteristics, previous experience, and perception of ADHD children. Knowledge of the Attention Deficit Disorders Scale (KADDS) was used to examine the participants’ level of knowledge of ADHD. Multivariable logistic regression analysis was performed to identify the variables associated with the participants’ tendency to recommend treatment to parents of ADHD students. Results The average correct rate was 64.4% on the KADDS. 64 (87.7%) participants had a positive perception of medical treatments of ADHD, but only 41 (56.2%) participants reported that they would recommend treatment to parents of ADHD children. Teachers that were older and married were more likely to recommend treatment. The teacher’s sense of efficacy was found to have a positive association with the tendency to recommend treatment to parents. Conclusion Educational programs and specific guidelines that can improve the knowledge of ADHD and self-efficacy as a teacher are needed for elementary school teachers. Teachers should understand that they have significant roles in the management of ADHD children.