Using and abusing of psychoactive substances affect both the behaviour of road users and the ability to drive. This fact ranks among the primary causes of mortality on roads together with speeding, fatigue, failure to use seat belts, crash helmets, etc. The problems of driving under the influence of psycho active substances have been for years a subject of numerous research projects in Europe and world wide. Since the 90s of the 20th century the increased activity in this area has been noted. In this paper the authors present the summary of analysis results regarding international context and their own observations as well. They deal with some legal aspects, problems with testing road users, precautions and the latest trends in research and implementation of the newly acquired knowledge. Moreover, the authors point out to an inadequate activity of Slovakia in this area at both national and international level. They stress the necessity of cooperation expanding between the responsible authorities within the Ministries of Transport and the Interior and forensic toxicologists and medical examiners.

Key words: road safety – psychoactive substances – driving under the influence – toxicological analysis