This study aimed to evaluate whether an intervention prevented the development of depressive symptoms through the early years of secondary school (Grades 7 to 9-mean ages 12.3 to 14.5 years) in Victoria, Australia. Twelve schools were randomized to a universal preventative intervention (including a student social relationship/emotional health curriculum, and parent/caregiver parenting education); 12 were randomized as control schools. Multivariate regression analyses used student self-report to predict depressive symptoms at 26-month follow-up (13-months after intervention completion) from baseline measures and intervention status (N = 2027). There was no overall intervention effect on depressive symptoms. However, intervention students with moderate symptoms whose parents attended parent education events had a significantly reduced risk of depressive symptoms at follow-up. Future evaluations of interventions of this type should investigate: therapeutic processes; methods to increase recruitment into effective parent education events; and the potential to target assistance to students with high depressive symptoms.