To evaluate how oral and general health-risk behaviours cluster among Brazilian adolescents. The study comprised a total of 109 104 adolescents (52.2% female) participating in the Brazilian National School-based Student Health Survey (PeNSE). Seventeen behaviours (including diet; oral and hand hygiene; frequency of dental visits; tobacco, alcohol and drug use; sexual behaviour; physical activity, and risk for external causes) were measured using a self-reported questionnaire. Pairwise correlations between the health-risk behaviours were performed, and clustering was assessed by the hierarchical agglomerative cluster analysis (HACA), which was used to identify stable cluster solutions of the health-risk behaviours. All health-risk behaviours were correlated with at least 1 behaviour (P < .01). HACA indicated 2 broad stable clusters (n = 105 604). The first cluster included current smoking, illegal drug use, no hand washing before meals, unprotected sex, no helmet use, less frequent toothbrushing, no seatbelt use, physical fighting, skipping breakfast, current drinking, high sugar intake and, at the final stage, no dental visits. The second cluster included insufficient physical activity, eating while watching TV or studying, and low fruit intake. The health-risk behaviours clustered into 2 specific patterns among Brazilian adolescents. One cluster gathered a combination of lack of adherence to preventive behaviours and the undertaking of risky conduct, while the second reflected an unhealthy lifestyle (sedentary habits and low fruit diet). Knowledge about the clustering patterns of oral and general health behaviours in adolescents can better direct the integration of oral and general health promotion interventions. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.