The aim of the present study was to investigate the factors associated with unintentional injury in children newly diagnosed with attention-deficit/hyperactivity disorder (ADHD). One thousand four hundred and thirty children between the ages of 6 and 18 who were diagnosed with ADHD for the first time in child psychiatry outpatient clinics were included in the present study. The socio-demographic information of the children, their developmental histories, chronic physical health conditions, comorbid psychiatric disorders, and information obtained via the Turgay DSM-IV-based Child and Adolescent Disorders Screening and Rating Scale were examined retrospectively. It was determined that 12.8% of the children (n = 183) experienced unintentional injury. It was established that age, male gender, disruptive behavioural problems, and low education levels among mothers were predictive of unintentional injuries. The results of the present study suggest that behavioural problems accompanying ADHD and comorbid psychiatric disorders are important in terms of unintentional injuries.