A number of developing countries are currently promoting vocational education and training (VET) as a way to build human capital and strengthen economic growth. The primary aim of this study is to understand whether VET at the high school level contributes to human capital development in one of those countries-China. To fulfill this aim, we draw on longitudinal data on more than 10,000 students in vocational high school (in the most popular major, computing) and academic high school from two provinces of China. First, estimates from instrumental variables and matching analyses show that attending vocational high school (relative to academic high school) substantially reduces math skills and does not improve computing skills. Second, heterogeneous effect estimates also show that attending vocational high school increases dropout, especially among disadvantaged (low-income or low-ability) students. Third, we use vertically scaled (equated) baseline and follow-up test scores to measure gains in math and computing skills among the students. We find that students who attend vocational high school experience absolute reductions in math skills. Taken together, our findings suggest that the rapid expansion of vocational schooling as a substitute for academic schooling can have detrimental consequences for building human capital in developing countries such as China.