Starting from the importance attached to ethnicity in contemporary Croatian society, this paper is based on research aimed at exploring the similarities and differences in attitudes regarding ethnic diversity expressed by two family generations in Croatia, secondary school pupils and their parents. The purpose of these attitude comparisons is to try to establish intergenerational similarities and differences, to determine their indicators and explain possible reasons for their occurrence. In the first part of the paper the authors indicate socialization aspects within the sociological theories of ethnicity and generation and outline the socio-historic context of the socialization of the studied family generations. In the central part of the paper the results of a survey conducted in 2009 are analysed on a convenience sample of secondary school pupils and their parents (N = 1902). The attitudes towards ethnic diversity and social distance towards members of selected ethnic groups (Albanians, Roma, Slovenians and Serbs) and foreign (migrant) workers are analysed. Although positive correlations in the expression of attitudes and social distance between secondary school pupils and their parents are obtained, t-test (paired samples method) resulted in some intergenerational differences. They are, among other, reflected in greater inclination among secondary school pupils towards ethnocentric attitudes, and closeness to cultural and ethnic diversity in comparison to their parents, while parents express significantly greater social distance towards Albanians, Slovenes and foreign workers compared to their secondary school children. Regression analyses conducted on each sub-sample tested the effect of socio-demographic, socio-cultural and socio-economic characteristics of respondents as well as their value orientation on the examined attitudes and expressed social distance. Finally, it is concluded that, on one hand, the results confirmed the importance of family in the process of ethnic socialization, and, on the other, the role of great social changes, especially traumatic socio-historical events, in both shaping attitudes towards ethnic diversity and in shaping generational characteristics.