The available information on the quality and frequency of illegal psychoactive substances used or medicines misused by workers, are often out of date at the time of its publication. This is due to the dynamic introduction of new synthetic drugs on the black market, changes in trends in the recreational use of medicines and the lack of readily available and reliable tests for fast identification. Strategy for detection of narcotic and non-medical psychoactive drugs use at workplace should embrace all possible sources of information. Classical sources of information on the use of psychoactive substances at the workplace include: statistical data (general information on trends and magnitude of drug and medicine addiction collected by the Polish National Police, the National Bureau for Drug Prevention and emergency medical services), surveys, psychomotor tests and qualitative and quantitative analyses of biological material. Of the new and promising methods, used throughout the world in recent years, chemical-toxicological analysis of surface water and wastewater deserve special mention. An increasing interest in the study of urban waste water can significantly complement the source of knowledge about drug and medicine addiction using obtainable conventional methods. In recent years, a municipal wastewater analysis has become a new and very promising way of collecting updated information on the use of psychoactive substances and medicines. It seems that this kind of study may play an important role in the ongoing monitoring of drug and/or medicines use by selected groups of population (e.g., students, military, firemen, policemen, etc.). Med Pr 2015;66(6):837–847