This paper examines trends in intergenerational class mobility for six birth cohorts of individuals born between 1921 and 1981, observed in surveys carried out in 1973, 1982, 1988, 1996 and 2014. Besides analysing the variation of trends on the basis of three temporal dimensions —age, birth cohort and survey year— the paper determines the effects of educational attainment on intergenerational mobility. The analysis reveals a historical trend of increasing social mobility across birth cohorts in Brazil. The effects of educational attainment are determined by three mechanisms: educational expansion, equality of educational opportunities and returns to education. While educational expansion is the main mechanism responsible for increasing mobility among the three younger cohorts of persons born between 1951 and 1981, the other two mechanisms play minor roles. In the period under review, the origin-destination class association, net of educational attainment, also declined and contributed to the increasing intergenerational mobility trend. Nevertheless, the expansion of higher education is the main reason for the increase in social mobility. This paper also examines racial disparities in intergenerational mobility. Despite the impressive educational expansion and increased mobility opportunities observed overall, the racial gap in intergenerational mobility opportunities does not change over time, with black people facing a greater probability of downward mobility.