[Contents] Executive Summary. Introduction. Methods. Results. Overview. 1. Participation. 2. Dietary behaviours and overweight. 3. Physical activity and sedentary behaviours. 4. Tobacco use. 5. Alcohol and other drugs use. 6. Sexual behaviours that contribute to HIV infection, other sexually transmitted infections and unintended pregnancy. 7. Bullying. 8. Mental health. 9. Protective factors. 10. Pocket money. Conclusions and recommendations. Overview. Conclusions. Recommendations. References 42. Appendices : Appendix I - Questionnaire. Appendix II - Detailed tables of results, by sex and age. Appendix III - Correlations between selected risk behaviours, age 13-15 years. Appendix IV - Fact sheet, age 13-15 years.