Acculturation has been associated with numerous health and social outcomes among Hispanic/Latino adolescents. Various self-report scales have been used to measure acculturation, making comparisons of results across studies difficult. This study administered several commonly-used acculturation scales to 221 Hispanic/Latino 9th grade students in Los Angeles. Although all of these scales purport to measure acculturation, the correlations among the scales, and their correlations with language usage measures, were modest. As expected, higher scores on Hispanic/Latino orientation scales (or lower scores on U.S./White orientation scales) were associated with higher levels of ethnic identity formation. Results indicate that these acculturation scales may measure different aspects of the complex phenomenon of acculturation. For example, purely language-based measures shared only small amounts of variance with more comprehensive measures. Additional research is needed to create and validate acculturation measures for adolescents.