This research report presents the findings of an evaluation of a school-based substance abuse prevention programme presented as part of Project Awareness. The programme was presented as a one-day intervention for grade ten learners in eleven schools in Tshwane. The prevention program taught substance abuse refusal skills, anti-substance norms, personal self-management skills, and general social skills in an effort to provide students with skills and information for resisting substance offers, to decrease motivations to use substances, and decrease vulnerability to substance use social influences. The study evaluated this school-based substance abuse prevention intervention in a sample of learners (N=300) in six of the eleven schools. Measures were obtained on a behavioural survey to ascertain whether any knowledge, behaviour or attitude change occurred between the pre-intervention and post-intervention phases. In addition, focus group data and observational measures were implemented to determine how the learners experienced the programme and whether the programme was effective in capturing the attention of the learners. Results indicated that, from learners perceptions of the programme, the intervention seems to have had a positive impact on substance abuse prevention, but not on changing the behaviour of learners already engaging in substance abuse. The results from the behavioural survey indicated some change in learner attitudes to some degree, but not behavioural change. Suggestions for the improvement of the programme were made throughout the report, and the observational measures specifically indicated that the more practical oriented tasks were more efficient in capturing the attention of learners. It is concluded that although the programme certainly had room for improvement, that the programme did indeed address relevant issues. The program also had a direct positive effect on several cognitive, attitudinal, and personality variables believed to play a role in adolescent substance use.