In this article, we address measurement issues related to select aspects of bullying involvement with the goal of moving psychometrically sound measurement practices toward applied bullying research. We first provide a nontechnical introduction to psychometric considerations in measuring bullying involvement, highlighting the importance of establishing measurement equivalence across contexts and intervention conditions. We then discuss different forms of data collection for antibullying-intervention evaluation, interinformant agreement, and benefits of using information from multiple reporters. In the third section, we address the importance of using valid and reliable measures of the different forms of bullying, particularly when measuring bullying involvement across development. Finally, we advocate for studying the larger peer ecology by capturing the different ways in which youth actively or passively participate in bullying incidents. We conclude with a brief consideration of how psychometrically sound measurement of bullying involvement can inform the development of appropriate, effective, evidence-based bullying interventions.