Attention-deficit/hyperactivity disorder (ADHD) is one of the longest recognised and most common neuropsychiatric disorders of childhood. Recent research indicates that ADHD is most often a lifelong condition associated with significant impairment in multiple domains of functioning. ADHD is a clinical diagnosis made on the basis of history and clinical examination. Current molecular, neuroimaging and neuropsychological studies have greatly elucidated our understanding of the basic science of ADHD. The underlying pathophysiology of ADHD has been theorised to be dysregulation of inhibitory noradrenergic frontocortical activity on dopaminergic striatal structures. Pharmacotherapy is recognised as the most effective component of ADHD treatment, although some role exists for proper educational placement, parent management training and social skills development. Methylphenidate and amphetamine are the current standards in ADHD medication treatment. Other medication classes such as tricyclic antidepressants and certain antihypertensives are also used in off-label therapy. Anticipated improvements in new ADHD medications include the development of extended release delivery systems, improved tolerability, alternative mechanisms of action and enhanced efficacy in treatment refractory cases.