The present double-blind study examined the effects of methylphenidate, cognitive therapy, and their combination in attention deficit-disordered (ADD) children. Four treatment groups were compared on measures of attentional deployment and cognitive style, tests of academic achievement, and behavioral rating scales. In contrast to a previous study conducted in this laboratory, children in this study were not receiving medication during post-testing. Results were interpreted to suggest that measurable effects of stimulant medication dissipate rapidly upon discontinuation of pharmacotherapy. The combination of methylphenidate and cognitive therapy was not found to be any more efficacious than either of the treatments studied alone. Discussion suggests that medication status at follow-up is an essential feature of research design.