Objective:To study changes in sexual behaviour related to HIV transmission in young people between 1988 and 1993.Design:Data collected by computer‐assisted telephone interview with 4081 individuals aged 18‐25 years resident in central Scotland. The data were collected on a monthly basis between 1988 and 1993 and aggregated into 11 6‐month periods. The data were examined for changes relating to condom use, numbers of sexual partners and perceived risk of contracting HIV.Methods:The statistical significance of observed changes over time in reported behaviours was assessed using a general linear modelling programme.Results:Increasing numbers of young men and women reported behaviour change because of HIV, using condoms, and concern that they or someone close to them would get AIDS. There is no evidence of a reduction in the number of sexual partners reported by men or women or a change in the number of individuals perceiving that they are at risk of HIV infection.Conclusions:Significant changes in sexual behaviour related to HIV transmission are taking place among young people in the general population; most notably an increase in the reported use of condoms by both men and women.