<p>Although microaggressions have been seen within a school context, there have been limited studies investigating bystander intervention in microaggressions among high school students. The current study, drawing from the bystander intervention model and the microinterventions framework addressed three aims: (1) examined the psychometric properties of a measurement tool created to measure bystander intervention in microaggressions among high school students, (3) tested whether each step of the bystander intervention model is associated with the subsequent step (e.g., the step of noticing the event and the step of interpreting the event as a problem), and (3) assessed the type of actions that high school students used when faced with microaggressions. Using a sample of 301 high school students, results were obtained and provided in terms of item-level analysis, item-to-subscale correlations, internal consistency, confirmatory factor analysis, structural equation model, and the percentage of respondents endorsing the different agreement levels for each intervention option. Implications for educators and future research are provided.</p>