The objective of this research is the assessment of the safety effect and the cost-effectiveness of the intensification of road safety enforcement in Greece in the period 1998-2002, with particular focus on two most important types of enforcement, namely speed and alcohol enforcement. On that purpose, data concerning the number of road accidents and related casualties, as well as the number of police speed and alcohol controls performed and violations recorded were used. Moreover, additional data on the amount and type of resources allocated in the enforcement scheme were obtained by means of interviews with Head Officers of the Police. The safety effect of enforcement was estimated by means of statistical models describing road safety, transport and demographic trends in various regions of Greece. A separate analysis was devoted to the estimation of accidents cost in Greece; especially as regards the estimation of human cost in road accidents, willingness-to-pay survey results were exploited. A cost-benefit analysis was eventually carried out, on the basis of the standard methodologies, according to which, speed and alcohol enforcement in the examined period in Greece was very cost-effective, both within a “conservative” and within a “best” estimation scenario.