The phenomenon of highly qualified Mexican migration has received little attention, and even less has been given to migrants with post-graduate studies. This is principally due to the scarcity of information sources to directly examine the number of qualified migrants worldwide and their characteristics. This paper offers an indirect estimate of the number of qualified Mexicans residing abroad, a figure estimated at 2.22 million in 2013. Drawing on data from the U.S. Census Bureau, this research analyzes the trends of highly qualified Mexican immigrants in the United States in 1990-2013. It also presents a descriptive analysis with ACS 2011-2013 data for migrants with post-graduate studies in the fields of Science, Technology, Engineering, and Mathematics (STEM).