Regarding which primary school teachers across the globe face the difficulty of teaching in an inclusive school, a broad range of ways exists to deal with the challenge. The primary characteristic of the students attending inclusive schools is that they experience attention deficit hyperactivity disorder (ADHD). This study aims to describe how teachers identify students with ADHD using a specific assessment instrument. Thus, it can make it easier for teachers to teach in class and provide special attention to students with ADHD. The data collection technique included semi-structured interviews with eight people comprising primary school class teachers, vice principals for student affairs, and school principals. The primary school teachers participating in this study have attended a workshop conducted by an expert in the Department of Special Education Need, teaching them how to use the assessment instrument in detecting ADHD. The data obtained were then analyzed and triangulated using qualitative data analysis techniques. Observations were made on teachers when assessing students with special needs having ADHD. The results revealed that the assessment conducted manually by the teacher by asking questions and paying attention to student attitudes with the ADHD instrument detected three categories: attention deficit disorder, excessive activity disorder, and self-control disorder. This study has implications for the primary school teachers and inclusive schools if they have ADHD students. It will help teachers detect students with ADHD syndrome.