A double-blind study was conducted to investigate the psychomotor effects of cigarette smoking on a 1-hour computer-based simulation of driving comprising continuous tracking and brake reaction time tasks. Twelve minimally abstinent smoker subjects were asked to operate the simulator on four occasions while smoking single cigarettes yielding varying levels of nicotine (< 0.1, 0.6, 1.0 or 2.1 mg) but similar levels (8–10 mg) of tar. Data were transformed with regard to baseline scores to counter day-to-day differences in performance and showed brake reaction times to be improved after all active treatments (p < 0.01) but tracking accuracy to be enhanced after the two cigarettes of middle strength alone (p < 0.05). These results suggest that, among smokers, cigarette smoking may improve driving performance and that there may exist an optimal nicotine dose for the enhancement of cognitive and psychomotor function.