This paper analyzes the development of social inequality in the Polish higher education system during its expansion after 1990 using data from the Polish General Social Survey. Focusing on the special case of a former socialist society, where higher education expansion has been very rapid and achieved mainly through marketization, this paper highlights the micro-level mechanisms that underlie the inequality dynamic. It shows how actor preferences embedded in the specific historical context shape educational behavior, producing moments of equalization and de-equalization. Class inequality regarding access to tertiary education decreased in the early 1990s and then increased again, as participation in the working classes stagnated at a low level in the later phases of the expansion. In contrast, no equalization has been observed between children of different educational origins. The analysis shows a persistent intergenerational reproduction of educational disadvantage in spite of the expansion. Lastly, consistent with the Effectively Maintained Inequality thesis, this paper provides evidence for underprivileged strata being diverted into second-tier, lower-prestige educational opportunities in the private sector.