This paper asks whether employment during high school impacts youths' grade point average. Unlike much of the prior literature, it allows for the endogeneity of the hours and dropout decisions, uses ASVAB test scores, and tests whether youth employment is dynamic. The results indicate that high school employment and its lag have small, negative impacts on academic grade point average for both males and females. The hours effects diminish when a fixed person effect is included, and they become statistically insignificant when hours are instrumented. (Contains 12 footnotes and 7 tables.)