Using data from the March Current Population Survey, the authors document an increase over the past 30 years in wage inequality for males. Between 1963 and 1989, real average weekly wages for the least skilled workers declined by about 5 percent, whereas wages for the most skilled workers rose by about 40 percent. The authors find that the trend toward increased wage inequality is apparent within narrowly defined education and labor market experience groups. Their interpretation is that much of the increase in wage inequality fro males over the last 20 years is due to increased returns to the components of skill other than years of schooling and years of labor market experience. Copyright 1993 by University of Chicago Press.