The migration of young Chinese scientists to undertake graduate studies in U.S. universities is arguably one of the most important recent episodes of skilled migration. Using a new data set covering around 16,000 Ph.D. graduates in 161 U.S. chemistry departments, we show that Chinese students have a scientific output during their thesis that is significantly higher than other students. In fact, conditional on acceptance into the same programs, Chinese students perform about as well as the awardees of the NSF doctoral fellowship program. These results shed new light on the benefits of student migration on scientific productivity of destination countries.