The high prevalence of children with Attention Deficit/ Hyperactivity Disorder (ADHD) in Indonesia has become a con-cern for nursing because ADHD might emerge as neurological developmental problems if not treated early through appropriate intervention. This study aims to determine the effectiveness of web-based play therapy on the emotional, behavioural and social development of school-age children with ADHD. This study employs a quasi-experimental non-equivalent control group design with purposive sampling technique, and 126 children with ADHD (patients at a psychiatric hospital in Indonesia) as partici-pants. The results show that play therapy is an effective intervention for the emotional, behavioural and social development of school-age children with ADHD (p = 0.048, p = 0.030, p = 0.030; α= 0.05). This study is recommended as a reference for optimising nursing care for children with ADHD using information technology in the form of web-based play therapy designed in line with the fundamentals of intervention for children with ADHD, using attractive features and flexible access. © the Author(s), 2023.