Assessment of neuropsychological functioning in adults with ASD has been researched for a while now, yet there seems to be no consensus on what the actual profile of impairment in this group of patients is. Conflicting results of various studies may be connected to many factors: heterogeneity of the clinical group, changes in diagnostic criteria, applied tests and assessment methods, trouble with matching healthy controls because of individual differences in neuropsychological functioning. The aim of the following paper is to analyse the selected domains of cognitive functioning in adult ASD individuals. It seems that the most consistent findings in this group are connected to central coherence and cognitive flexibility which in turn affect social functions and repetitive behavioral patterns - two core issues of ASD patients. The implications of those findings for clinical practice and diagnostic approach to adult ASD patients are discussed. Especially in regards to high-functioning ASD individuals whose neuropsychological impairment may not show in a standard neuropsychological assessment.