The ISSP Social Inequality module consists of three surveys from 1987, 1992 and 1999. The 1999 survey is a partial replication of the 1992 study and the 1992 survey a partial replication of the 1987 study. The next survey on Social Inequality is planned for 2009.

The ISSP Social Inequality module mainly deals with attitudes towards income inequality, views on earnings and incomes, legitimation of inequality, career advancement by means of family background and networks, social cleavages and conflict among groups, and the current and past social position.