General insight into the frequency and gravity of cognitive dysfunctions following stroke and its influencing factors is still lacking. With an extensive neuropsychological battery 229 patients who had suffered a stroke were assessed. More than 70% of the patients showed a marked slowness of information processing, whereas at least 40% of all patients had difficulty with memory, visuospatial and constructive tasks, language skills, and arithmetic. A significant effect was found for side and type of stroke, gender, and the presence of aphasia. No significant effect was found for cortical versus subcortical lesions, having one versus multiple strokes, having lowered consciousness on admission, the presence of risk factors, a paresis of the hand, or the interval between the stroke and the neuropsychological assessment.