This article outlines evidence of the longitudinal association between individual risk factors (i.e., lifestyles and behaviours) and non-suicidal self-injury (NSSI) in adolescents. The authors carried out a systematic review with meta-analysis to highlight potential risk factors associated with NSSI. The findings can help identify lifestyle factors and behaviours that might contribute to a greater likelihood of NSSI. This knowledge can help inform prevention strategies, early interventions, and targeted treatment for adolescents.