Since 2008, it has been recognised by most health authorities worldwide that the abuse of newly-emerging psychoactive drugs, (‘designer drugs’/‘legal highs’; DD), in youth is a rapidly increasing problem, especially in the EU, threatening to offset gains made in tackling established and illegal drugs which they are intended to mimic; DD diversity is continually increasing to circumvent laws. The aim of the study was to determine the scale of DD abuse/availability amongst Polish youth. The surveyed test population was randomly selected from a representative group of adolescents attending high schools, secondary schools and universities throughout Poland. Questionnaires were completed by 14,511 subjects (10,083 school pupils and 4,428 students). Few persons from each group admitted using DDs; 453 school pupils (4.49%) vs. 81 students (1.83%). More males (4.74%) took DDs than females (2.77%). The tendency to take DDs in the company of friends was high in both DD-taking groups (>80%). DDs were consumed mostly in open spaces (34.15%), discos/pubs (21.13%) and boarding school/friend’s house (20.57). Most frequently, DDs came from shops (57.68%), friends (31.46%) or dealers (10.11%). Ensuing symptoms included; happy/euphoric mood (58.80%), talkativeness (42.51%) and hallucinations (22.85%). Over 74% of DD-takers in both groups experienced adverse reactions, and those requiring help sought it from: friends/colleagues (6.74%), doctors (5.06%), and hospitals (4.87%), but most rarely from parents/guardians (2.62%). Urgent action is being taken, especially in youth education, to prevent DDs becoming the serious menace seen with conventional drugs.