"Legal highs" known also as "smarts", "legal drugs" or "boosters" contain in their composition psychoactive substances the production, sale and possession of which are not prohibited in legislation. They are offered for sale under the cover of collectors' items, a salt bath, aroma sticks, or plant fertilizer. Marketing was the reason for such high sales of these "highs" in Poland. The phenomenon became of concern when information became available about the first cases of tragic health consequences. Raising the awareness of youth about the level of imminent danger and serious consequences associated with the use of legal highs may be a very effective way to develop appropriate attitudes of young people, and in the light of their own health can help them take proper life decisions."Legal highs" are substances of natural or synthetic origin having psychostimulating properties. These compounds may differ in chemical structure, potency, half-life, metabolism and severity of side effects. Their pharmacological activity is associated with changes in the neurotransmitter system. After higher doses of "legal highs" psychotic symptoms may occur: visual and auditory hallucinations resembling schizophrenic endogenous psychoses. An alarming fact is the underestimation of the adverse effect of these substances on human health. Any actions aimed at improving this situation are extremely important; therefore, in one of the key projects undertaken at the Institute of Rural Health in Lublin, in cooperation with other scientific institutes, concerned the analysis of a selected series of "legal highs". This research was meant top serve as a source of information for science and medicine, and for popularizing knowledge about legal highs.