The transition from middle school to high school is an important developmental period to investigate because of the negative impact it has on youths' academics. The purpose of this study was to investigate Latino youths' academic achievement prior to, during, and after the transition to high school, and gender differences in youths' achievement over time. School transcripts were obtained for 92 youth. Three latent growth curve models were tested. Youth were stable in achievement throughout middle school, declined in grades during the transition, yet remained stable in high school. Youth with higher achievement in fall of eighth grade declined in the transition at a faster rate than youth who held lower achievement. Girls held higher levels of achievement across each stage in development; boys and girls differed in high school trajectories. Policy makers interested in fostering a successful transition should create programs for both high- and low-achieving Latino youth.