Objectives: This study examined decision-making competence in ADHD by using multiple decision tasks with varying demands on analytic versus affective processes. Methods: Adults with ADHD and healthy controls completed two tasks of analytic decision making, as measured by the Adult Decision-Making Competence (A-DMC) battery, and two affective decision tasks (the Balloon Analog Risk Task and the lowa Gambling Task). Results: Although a majority of the ADHD participants were tested under medication, they showed impairments in both types of task. However, logistic regression analysis showed that the applying-decision-rules task of the A-DMC battery was the only significant predictor of ADHD status. Conclusions: These findings suggested that ADHD is associated with impaired decision making in tasks involving a significant degree of cognitive control. Although both deliberative and affective neurocognitive systems probably contributed to ADHD-related problems in decision making, the findings underlined the involvement of prefrontally mediated executive functions. (Contains 1 figure, 4 tables and 1 note.)