Attention-Deficit/Hyperactivity Disorder (AD/HD) is now recognised as a chronic condition that continues into adulthood. A great deal of research has been done to validate the diagnosis in adults, but studies of the neuropsychological, psychological and functional outcomes of adults with AD/HD have been inconsistent. In addition, there is an assumption that underlying neurological deficits are responsible for the poor functional outcomes found among adults with AD/HD, yet this association has not been demonstrated empirically. Sixteen adults with AD/HD, Inattentive subtype, 16 adults with AD/HD, Combined subtype, and 30 control adults matched to the AD/HD adults by gender, age, years of education and estimated IQ were compared on a battery of attention, memory, and executive functioning tests. A number of methodological changes were made in an attempt to address the limitations of previous studies, and to characterise adult AD/HD more accurately. In addition all participants completed self report inventories of depression, anxiety, stress, social, vocational, family/home, and financial functioning. The relationships between variables were examined to determine whether neuropsychological deficits are related to functional outcomes in the AD/HD group.