There is a paucity of test-retest reliability data for adolescent self-reports of a wide range of risk behaviours. Grade 8 and 11 students (N = 358) completed a questionnaire on two occasions between 10 and 14 days apart. It included items about use of various substances, violent behaviour, suicidality, and sexuality. Cohen's kappa was almost perfect for 1 item (kappa = 85.4%); in the substantial range (61-80%) for 4 items; and in the moderate range (41-60%) for 3 items. For the remaining 7 items, the percentage agreement was higher than 92.0%. The questionnaire thus demonstrates adequate test-retest reliability.