Objective: Teen dating violence is a serious public health problem. A cluster-randomized trial was conducted to assess the efficacy of Teen Choices, a 3-session online program that delivers assessments and individualized guidance matched to dating history, dating violence experiences, and stage of readiness for using healthy relationship skills. For high-risk victims of dating violence, the program addresses readiness to keep oneself safe in relationships. Method: Twenty high schools were randomly assigned to the Teen Choices condition (n = 2,000) or a Comparison condition (n = 1,901). Emotional and physical dating violence victimization and perpetration were assessed at 6 and 12 months in the subset of participants (total n = 2,605) who reported a past-year history of dating violence at baseline and/or who dated during the study. Results: The Teen Choices program was associated with significantly reduced odds of all 4 types of dating violence (adjusted odds ratios ranging from .45 to .63 at 12 months follow-up). For 3 of the 4 violence outcomes, participants with a past-year history of that type of violence benefited significantly more from the intervention than students without a past-year history. Conclusions: The Teen Choices program provides an effective and practicable strategy for intervention for teen dating violence prevention. (PsycINFO Database Record (c) 2016 APA, all rights reserved)