The objective of this research is the analysis of the driving performance of drivers with Alzheimer’s disease (AD) and Mild Cognitive Impairment (MCI), on the basis of a driving simulator experiment, in which healthy “control” drivers and impaired drivers drive in different driving scenarios, following a thorough neurological and neuropsychological assessment of all participants. The driving scenarios include driving in rural and urban areas in low and high traffic volumes. The driving performance of drivers impaired by the examined pathologies (AD and MCI) is compared to that of healthy controls by means of Repeated Measures General Linear Modeling techniques. In this paper a sample of 75 participants is analyzed. Various driving performance measures are examined, including speed, lateral position, steering angle, headway, reaction time at unexpected events etc., some in terms of their mean values and some in both their mean values and their variability. The results suggest that the two examined cerebral diseases do affect driving performance, and there are common driving patterns for both cerebral diseases, as well as particular characteristics of specific pathologies. More specifically, drivers with these cerebral diseases drive at lower speeds and with larger headway compared to healthy drivers. Moreover, they appear to have difficulties in positioning the vehicle on the lane. Cerebral diseases also appear to significantly affect reaction times at incidents.