The doctoral thesis Structural and Cultural Individualization in Croatian Society Between 1999 and 2018 includes theoretical and empirical research on the process of individualization as an important dimension of modernization processes and value changes in contemporary societies. The first part of the thesis offers an overview of the most important theories on individualism and individualization, which includes the works of many authors: from Tocqueville, Simmel, Durkheim and Weber to Beck, Beck-Gernsheim, Bauman and Giddens. After a review of relevant theoretical works, the results of previous empirical research on the topic in question are presented. Among the researchers represented are Inglehart, Hofstede, Schwartz, Triandis, Halman and others. The next part concerns the conceptualization of the main phenomena. Based on an analytical approach to the corpus of classical and contemporary social theories and previous empirical research, individualization is divided into structural and cultural individualization. While structural individualization is conceptualized as liberation from the bonds of social structures, institutions and roles, cultural individualization is seen as an increase in individualistic value orientations that are reflected in the decline of collectivism, solidarity, and social responsibility as universal value orientations. The research objectives of the thesis were to analyze the trends of structural and cultural individualization in Croatian society, with reference to the European context; to investigate the connections between structural and cultural individualization in Croatian society; and to investigate the connection between structural and cultural individualization by implementing multilevel regression models in the context of selected European countries. In accordance with the stated goals, the main hypothesis Cultural individualization is correlated to structural individualization was tested and confirmed. In addition to the main hypothesis, hypotheses about the growing trend of structural and cultural individualization and auxiliary hypotheses about the connection were tested, which refer to certain dimensions of cultural individualization as a dependent variable and structural individualization as a predictor set of variables. Using the variables from the databases of the European Values Study from 1999, 2008 and 2018, the respective concepts were operationalized and converted into indices and scales that were used in correlation analyses. Within most of our indicators, a growing trend of structural individualization was established. In the case of cultural individualization, there is no unequivocal pattern, however none of the indicators had the highest value in the last wave of research. Multilevel regression analyses revealed that the degree of cultural individualization is mostly influenced by indicators of structural individualization at the micro-level, and most macroindicators are not related to cultural individualization. Significant and positive correlations between structural individualization and anomic individualism and egoistic individualism (social indifference and identity indifference) were found, while correlations between structural individualization and economic individualism were mostly negative. Individualized political participation was negatively related to cultural individualization, which indicates a positive effect of individualized civic participation on social solidarity and cohesion. The scientific contribution of this doctoral thesis is reflected in the fact that the process of individualization was approached with an innovative theoretical-conceptual framework and empirical indicators from several domains and at several levels of analysis.