Cognitive ability is essential for the fitness to drive. Impaired cognitive functions are common after cardiac surgery. Little is known about driving habits and influence of postoperative cognitive decline on driving performance in these patients. The aim of this study was to investigate the extent of driving activity of patients before and after cardiac surgery. Ninety-seven cardiac surgical patients were interviewed about their driving habits before and 12 weeks after surgery. The mean age was 66. Before the operation, 78% were active car drivers. They drove several times a week including longer than 100 km distances. After the operation, 64% continued to drive and most of them (69%) had commenced driving within 6 weeks. The majority (79%) reported unchanged driving habits, while 13 patients (21%) had reduced their driving activity due to the cognitive symptoms they experienced. Patients with coronary artery disease are active car drivers both before and after heart surgery. Further evaluation of the ability of these patients to drive is required if we are to give advice and apply restrictions in the interest of traffic safety.