In a small (n = 15) clinically heterogeneous group of patients with dementia of the Alzheimer-type or vascular dementia, abnormally high frequency of saccadic intrusions during fixation was significantly correlated to the Mini-Mental-State-Examination (MMSE) scores. In addition, the latency of saccades and hypometric saccades also correlated significantly to MMSE-scores. The results point to the possible use of saccadic eye movement as a physiological marker of cognitive performance.