Objective: To evaluate whether a dichotic memory test would reveal deficits in short-term working-memory recall and long-term memory recall in a group of adult patients with ADHD. Methods: A dichotic memory test with ipsilateral backward speech distraction in an adult ADHD group (n = 69) and a control group (n = 66) is used to compare performance between the groups and inside the subgroups of ADHD diagnosed with "DSM-IV." Results: The ADHD participants showed significant impairment in the dichotic memory test compared with control participants when controlled for age, sex, and education. Study findings reveal that there is no difference in subdivision in the three ADHD subgroups of "DSM-IV" A discriminant analysis shows an overall classification rate of 78% and specific in ADHD 80%. Conclusions: The results indicate that the dichotic test is measuring one of the important ADHD deficits. (Contains 2 tables.)