Aims. To monitor young people's experience and knowledge of illicit drugs between 1969 and 1999 at intervals of 5 years. Design. The same confidential anonymously completed questionnaire was used throughout. Setting. Three secondary schools in Wolverhampton, an English Midlands town. Participants. Two hundred and seventy-four pupils aged 14-15 completed the questionnaire in 1999. Previous sample sizes were 471 in 1969, 523 in 1974, 648 in 1979, 540 in 1984, 380 in 1989 and 392 in 1994. Measurements. Self-reported levels of experience and knowledge of illicit drugs. Findings. Over 30 years the proportion of pupils who knew someone taking drugs more than quadrupled from 15% (71/461) in 1969 to 65% (254/392) in 1994 and decreased to 58% (157/273) in 1999. The proportion who had been offered drugs increased nine-fold from 5% (24/462) to 45% (175/392) and levelled to 48% (131/274) in 1999. The proportion mentioning “ecstasy”, LSD and amphetamines increased while amyl nitrite decreased significantly. “To feel big, grown up” was the main perceived reason for taking drugs. “To escape problems” increased significantly in 1999. Television remained the main source of information closely followed by friends and talk in school. Conclusions. The experience of illicit drugs, after increasing dramatically to a peak in 1994, has levelled out in 1999. Although the knowledge of the names of drugs has steadily increased, knowledge of the effects has remained limited. Social and group pressures remain the main perceived reason for taking drugs and many may see drugs as a way of coping with stress. Progress in education about drugs must take account of wider issues in society.