OBJECTIVES: This study examined comparative safety of stimulant versus atomoxetine with the risk of neurological adverse events in children with Attention-Deficit/Hyperactivity Disorder (ADHD). METHODS: The IMS LifeLink Health Plan Claims Database was used for this retrospective, propensity score matched analysis of children and adolescents with ADHD on stimulant and atomoxetine. The study sample included children less than 18 years of age initiating stimulant or atomoxetine therapy between July 1, 2004 to December 31, 2005. Patients with stimulant and atomoxetine were matched on propensity scores calculated based on baseline characteristics. The neurological adverse events included tics disorder (ICD-9-CM code-307.2x) and seizures (ICD-9-CM codes- 345.xx, 780.3, 780.39, 780.31). Conditional logistic regression was used to account for the matched pair design. The final logistic model was adjusted for duration of therapy/persistency along with other covariates which were significant after matching. Sensitivity analysis was also performed using pharmacotherapy as the main outcome measure for management of neurological adverse events RESULTS: The propensity score matched cohort consisted of a total of 7,424 children with ADHD (3,712-Atomoxetine users and 3,712-Stimulant users). Conditional logistic regression revealed that stimulant or atomoxetine use did not differ in terms of the risk of neurological adverse events development (Odds Ratio [OR]- 0.86; 95% Confidence Interval [CI]- 0.57-1.28). However, central nervous system pathology was significantly associated with the development of neurological adverse events (OR-2.87; 95% CI-1.19-6.92). Sensitivity analysis showed that stimulant use (OR-1.36; 95% CI- 1.18-1.56) was positively associated with the treatments for neurological adverse events. CONCLUSIONS: Stimulant use was not significantly associated with diagnosis of neurological adverse events compared to atomoxetine in children. However, sensitivity analysis revealed that the stimulant users had an increased chance of receiving treatments for neurological adverse events. The findings suggest that stimulant use can lead to neurological adverse events which are not documented in ADHD patients but are usually treated.