The article discusses the relationship between educational attainment and the existence of cohabitation in the Czech Republic. Cohabitation of unmarried partners is a timely topic given a constant growth of this form of relationship in the Czech society, which almost tripled between the years 1991 and 2011. Based on data from the ISSP 2012 quantitative survey, the article seeks to demonstrate whether the educational attainment of an individual or his/her partner is associated with whether or not they cohabitate. Cohabitation is juxtaposed to marriage as well as to living-apart-together relationships, with partners living in different households. Where methodologically feasible, the findings are verified on data from the following surveys: European Value Study 2008, Our Society 2012 and European Social Survey 2012. However, most of the analyses rely exclusively on the more robust dataset of ISSP 2012. When split into the different categories of relationship and educational attainment, the other datasets analyzed did not provide sufficient samples for the necessary analyses. The article builds on the socioeconomic Rational Choice Theory (Becker) and normative theory (Inglehart, Van de Kaa). RCT is primarily applied to the relationship between education and postponing marriage or cohabitation, while normative theory provides a perspective on the effect of education-related values on alternative relationship preferences or the decision never to marry. In the analysis, we first verify whether educational attainment affects an individual's relationship form (cohabitation vs. marriage). To determine the association between specific variables, we applied the chi-square test of independence (for the education variable recoded into three categories) and the non-parametric Mann-Whitney U Test (for the original scale variable). We were unable to confirm an immediate relationship between education and cohabitation in either of the datasets analyzed-the same results were attained when the analysis was replicated on EVS 2008, Our Society March 2012 and ESS 2012 data. The authors suggest two possible interpretations of this finding. First, the perceived difference between long-term cohabitation and marriage is gradually decreasing in the Czech Republic. This argument is supported by the use of the term "de-facto marriage" as an equivalent of cohabitation in the Czech context. The second possible interpretation is based on the effect of factors that motivate both low-education and higher-education individuals to postpone marriage, namely lack of funds among the former and preference of education and career among the latter. In the second part of the analysis, we study the relationship between educational attainment and cohabitation versus living-apart-together relationships. We tested the relationship using the non-parametric Mann-Whitney U Test on the original scale education variable. The analysis was performed on unmarried (divorced, widowed or single) individuals who have a partner. A difference was observed in the group of d...