Although evidence supports the use of double-blind placebo medication trials to evaluate methylphenidate (MPH) effects on the core behavioral symptoms of attention-deficit/hyperactivity disorder (ADHD), few studies have demonstrated their utility in examining MPH effects on the cognitive deficits associated with ADHD. This article presents a technique for evaluating behavioral and cognitive dose-response relationships at the single-subject level of analysis. Case study results and multivariate analyses suggest that systematic evaluation of behavioral and cognitive MPH dose-response relationships could lead to more accurate MPH titration and greater long-term multimodal treatment efficacy.