Attention-deficit/hyperactivity disorder (ADHD) affects approximately 8-10% of school-aged children in the US and for many individuals persists into adolescence and adulthood. Both pharmacological and nonpharmacological (behavioural) therapies are used to treat individuals with ADHD. Treatment with stimulant medications, which include methylphenidate and amphetamine, typically requires multiple daily doses to maintain efficacy. The frequency of treatment, coupled with the importance of timing of doses and the long-term nature of treatment, make noncompliance a particular issue in the treatment of ADHD. Studies report noncompliance rates of 20-65% with stimulant treatment, although there are only limited published studies and these show considerable individual variation. Noncompliance can arise through inadequate supervision of those receiving medication, leading to delayed or missed doses, or through the reluctance of individuals to take medication, which is influenced by a number of factors (e.g. social attitudes, pressures or worries surrounding medication use and the inconvenience of multiple daily doses). Two approaches are likely to increase compliance with stimulant treatment: effective once-daily formulations of medication and improved treatment information. The development of effective once-daily formulations for stimulant treatments removes the need for multiple daily doses, with the associated problems of ensuring adequate treatment supervision and personal privacy. Improved provision of education and information for individuals with ADHD, as well as their families and teachers, should help them address the issues surrounding stimulant medication and allow full participation in the treatment process. Together, these strategies should improve treatment compliance for individuals with ADHD.