Objective: The goal of this study is to investigate decision making in children with ADHD using a child version of the Iowa Gambling Task (IGT). The effect of internalizing symptoms is also of interest. Method: Twenty-one children with ADHD (high anxiety/depression and no anxiety/depression) are compared to an age- and sex-matched control group on the gambling task. Children in the ADHD-alone group demonstrate impaired performance on the IGT. In contrast, children in the control group and the ADHD-anxiety/depression group learn to choose more from the advantageous decks over time. Results: These findings of impaired decision making in children with ADHD parallel findings of real-life decision-making problems in this population. Conclusion: Furthermore, the findings suggest that having a high number of internalizing symptoms leads to better performance for children with ADHD on this variant of the IGT. (Contains 1 table, 2 figures, and 2 notes.)