OBJECTIVE To investigate influential factors for the tendency to medicate and medication compliance in children with attention deficit hyperactivity disorder (ADHD). METHODS A total of 188 children aged from 5 to 16 years, who were initially diagnosed with ADHD according to DSM-IV criteria, were included in the study. They underwent symptom assessment and cognitive function test. The compliance of methylphenidate treatment was evaluated. RESULTS Patients with better emotional state, and fewer oppositional and hyperactive behaviors and those who had a family history of psychiatric diseases and who obtained lower scores in the number cancellation test (NCT), were more prone to medication and/or exhibited better medication compliance. Logistic regression analysis showed that fewer oppositional and hyperactive behaviors and lower NCT scores were the predictive factors for a higher tendency to medicate, and a better emotional state was the predictive factor for better medication compliance. Patients of predominantly inattentive type were more prone to medication and showed better medication compliance, as compared with those of combined type. Gender, age and symptom severity were not associated with the tendency to medicate and/or medication compliance. CONCLUSIONS There is a need to enhance medication compliance in children with ADHD who have hyperactive, impulsive and oppositional behaviors, and to improve their long-term social functions.