This study tested the hypotheses that older adults make less advantageous decisions than younger adults on the Iowa Gambling Task (IGT). Less advantageous decisions, as measured by the IGT, are characterized by choices that favor larger versus smaller immediate rewards, even though such choices may result in long-term negative consequences. The IGT and measures of neuropsychological function, personality, and psychopathology were administered to 164 healthy adults 18–85 years of age. Older adults performed less advantageously on the IGT compared with younger adults. Additionally, a greater number of older adults' IGT performances was classified as “impaired” when compared with those of younger adults. Less advantageous decisions were associated with obsessive symptoms in older adults and with antisocial symptoms in younger adults. Performance on the IGT was positively associated with auditory working memory and psychomotor function in young adults, and in immediate memory in older adults. (JINS, 2007, 13, 480–489.)