Mexico experienced a pronounced increase in the degree of inequality and earnings inequality over the 1980s and mid 1990s. Contrary to the trend in the distribution of total income inequality, there has been an improvement in the distribution of earnings inequality since 1996. This paper shows the following results. First, education has the highest gross contribution in explaining changes in earnings distribution. Second, both changes in the distribution of education and in the relative earnings among educational groups have always been in phase with the alterations in the earnings distribution. Specifically, when the income profile effect related to education became steeper and the inequality of education increased, the earnings distribution worsened (as in the 1988-96 period). Third, changes in the relative earnings among educational groups are always the leading force behind changes in inequality.