The purpose of this study was to investigate the latent structure of the Learning and Study Strategies Inventory-High School (LASSI-HS) through confirmatory factor analysis and factorial invariance models. A simple modification of the three-factor structure was considered. Using a larger sample, cross-validation was completed and the equality of factor structures was compared across gender and ethnicity. Participants for the confirmation of the three-factor model were 115 above-average-ability and average-ability seventh through ninth graders of middle and upper middle socioeconomic status. For the cross-validation and the factorial invariance analysis, existing data from 367 ninth graders were used. Factorial invariance was found across gender but not across ethnic groups. The LASSI-HS likely offers valuable information about students' learning strategies, but caution is warranted when making comparisons across cultural groups.