In this article we present a review of problems associated with cognitive dysfunctions in multiple sclerosis (MS). Neuropsychological investigations demonstrated that cognitive dysfunctions are common in MS patients and affect 40-65% of them. Cognitive deficits were found mainly on measures of memory, attention, information-processing speed, executive functions and abstract reasoning. The differences and degree of cognitive dysfunctions in MS are highlighted and usually related to different clinical appearance (clinical course, duration, disability level, treatment type). Furthermore, we have reviewed published correlations between psychopathological dysfunctions and neuroimaging results (mainly MRI techniques and functional imaging). The results of these correlations showed that an important role in cognitive impairment is related to the total lesion area, the severity of the pathological damage of the normal-appearing brain tissue (NABT), and brain atrophy.