Adult attention deficit/hyperactivity disorder (ADHD) is an increasingly recognized disorder with associated psychiatric comorbidity and impairment. Although pharmacotherapy serves an important role in treating ADHD and other concurrent psychiatric disorders in children and adolescents, the use of pharmacotherapeutics for adults with ADHD remains less established. In this report, the effectiveness and dosing parameters of the various agents investigated for adult ADHD are reviewed. A systematic review of the available literature identified 7 studies (N = 193 subjects) of psychostimulants and 10 studies of nonstimulant medications (N = 167 subjects) including antidepressants, antihypertensives, and amino acids for the treatment of ADHD in adults. The majority of double-blind investigations were with the psychostimulants, with the nonstimulant agents, generally antidepressants, studied under open conditions. There was considerable variability in diagnostic criteria, dosing parameters, and response rates between the various studies. Under controlled conditions, the aggregate literature shows that the stimulants had a clinically and statistically significant effect on reducing ADHD symptoms. Open studies on the nonserotonergic antidepressants (tricyclics, bupropion, and monoamine oxidase inhibitors) also show a moderate anti-ADHD effect. The literature appears to support the use of robust doses of both stimulants and antidepressants for ADHD in adults. Further controlled studies applying stringent diagnostic criteria and outcome methodology are necessary to define the range of pharmacotherapeutic options for adults with ADHD.