Attention-deficit/hyperactivity disorder (ADHD) is one of the most prevalent disorders in the child and adolescent population, with a known impact on learning, social relations and quality of life. However, the lifestyle habits of patients with this disorder have been poorly studied.A total of 160 children and adolescents, aged between 6 and 16 years, participated in the study. Half of them were treatment-naïve patients with a clinical diagnosis of ADHD according to DSM-IV-TR criteria, and without comorbidities. The remaining 80 participants were typically developing (TD) controls without known neurodevelopmental or psychiatric disorders. Parents of all participants completed a questionnaire about their children´s lifestyle habits (e.g, daily hours of sleep, media use and study).The groups had a similar socioeconomic background and did not differ with respect to age and sex distribution. However, patients with ADHD spent more time than TD children studying, and less time watching TV, playing video games, using computers and playing with other people. They also slept fewer hours per night than children and adolescents with TD. ADHD and TD groups spent similar time reading, listening to music and playing sports.The results of this study suggest that children and adolescents with ADHD have different lifestyle habits compared to age- and sex-matched controls. These findings are not explained by comorbid disorders or medication/ psychological treatment.