PURPOSE: To evaluate the relationship between sociodemographics and the prevalence of bullying victimization and perpetration using single-item and multiple-item measures. METHODS: Longitudinal survey data were obtained from 4297 children at fifth, seventh, and tenth grade in three U.S. cities. Bullying victimization and perpetration were measured in two ways: 1) a single-item recall measure; and 2) a separate multiple-item measure using specific behaviors indicating bullying victimization and perpetration. Multilevel logistic regression modeled the relationship between sociodemographics and bullying, stratified by measurement type. RESULTS: In fifth grade, 4% of children were identified as victims using the single-item approach but not the multiple-item approach, 27% were identified as victims using the multiple-item approach but not the single-item approach, and 17% were identified as victims using both approaches. For perpetration, 3% were identified using the single-item approach but not the multiple-item approach, 18% were identified using the multiple-item and not the single-item approach, and 4% were identified using both approaches. The odds of victimization were significantly lower in seventh and tenth grades than in fifth grade using both approaches. The single-item odds of perpetration were significantly lower in tenth grade than fifth grade, but the multiple-item odds of perpetration significantly increased over time. CONCLUSIONS: Bullying prevalence rates are sensitive to the structure of measures. Future research should identify whether these differences reflect a lack of awareness of types of bullying and/or cognitive variability in answering sensitive survey questions.