The objective of this study is to evaluate a novel sequenced combination of a promising, computerized cognitive training program targeting working memory (WM) deficits in children with attention-deficit/hyperactivity disorder (ADHD) in combination with behavioral parent training, a well-established, evidence-based intervention for ADHD. The combined active intervention, compared to the combined control intervention will result in improvement in primary psychosocial (i.e., parent/teacher reported child impairment; parental stress; parenting behavior; and observed child academic achievement) and psychiatric (parent/teacher rated ADHD, ODD, and CD symptoms; observed activity level and attention) outcomes at post-treatment and follow up assessment, with the combined active intervention resulting in greater improvements in these outcomes.