PURPOSE: To test a behaviorally specific measure of serious peer victimization, called aggravated peer victimization (APV), using empirically derived aggravating elements of episodes (injury, weapon, bias content, sexual content, multiple perpetrators, and multiple contexts) and compare this measure with the conventional Olweus bullying (OB) measure, which uses repetition and power imbalance as its seriousness criteria. METHODS: The data for this study come from The National Survey of Children's Exposure to Violence 2014, a study conducted via telephone interviews with a nationally representative sample. This analysis uses the 1,949 youth ages 10-17 from that survey. RESULTS: The APV measure identified twice as many youth with serious episodes involving injury, weapons, sexual assaults, and bias content as the OB measure. In terms of demographic and social characteristics, the groups were very similar. However, the APV explained significantly more of the variation in distress than the OB (R2 = .19 vs. .12). CONCLUSIONS: An empirical approach to identifying the most serious incidents of peer victimization has advantages in identifying more of the youth suffering the effects of peer victimization. Moreover, its behaviorally specific criteria also bypass the difficult challenge of trying to reliably assess what is truly bullying with its ambiguous definitional element of power imbalance.