BACKGROUND: Negative attitudes of physiotherapists may prevent them from implementing exercise as an intervention among people with disabilities. The aim of this study was to examine whether physiotherapy student attitudes towards the barriers to exercise for adolescents with Down syndrome changed as a result of participating in a 10-week exercise programme. METHOD: Data were collected as part of a randomised controlled trial. Twenty physiotherapy students (2 men, 18 women; mean age 19.5±1.3 years) volunteered to act as mentors. Each mentor was matched with an adolescent with Down syndrome from the same metropolitan suburb, who had been randomly allocated to either the intervention or the control group. The 10 adolescents and students in the intervention group all completed a 10-week, twice a week progressive resistance exercise training programme. The 10 adolescents and students in the control group continued with their usual activities. The students completed the 18-item Exercise Barriers Scale at baseline and after 10 weeks. RESULTS: There was a positive change in attitudes, significant at the p <0.05 level, favouring the intervention group on 9 of the 18 items on the Exercise Barriers Scale. CONCLUSIONS: After engagement in a 10-week exercise programme with an adolescent with Down syndrome, physiotherapy students identified fewer barriers that would prevent adolescents with Down syndrome from exercising. Results indicate that contact with adolescents with Down syndrome during clinical placement can positively influence attitudes towards exercise for people with Down syndrome among physiotherapy students.