Iowa Gambling Task is one of the most commonly used tools in the neuropsychological assessment of the decision making process. It was designed to assess decision making in patients with damage to their prefrontal cortex. Up to date, it has been used in studies of healthy subjects and numerous clinical populations. The aim of this paper is to enclose construction and administration of the test as well as to review results of studies in which it was applied. Construction of the Polish version of the tool and results of the studies performed with it are also presented.