One of the most important factors contributing to the increasing diversity of family trajectories is the growing prevalence of unmarried cohabitation and extramarital births. Using data from the ‘Social and Economic Conditions of Motherhood’ survey (SEPM) from 2006, this paper explores the factors influencing the probability that an unmarried mother will marry after childbirth. The findings show that for one ‑third of unmarried mothers in the Czech Republic unmarried parenthood is the first phase in the family life ‑course leading to marriage rather than long term family arrangement. Unmarried mothers living in unmarried cohabitation, women with higher education, and women who have postponed marriage due to pregnancy have a higher probability of making the transition to marriage. The analysis does not confirm that the uncertainty of the relationship and a partner’s negative attitudes towards marriage at the time of childbirth have negative effects on the transition to marriage after childbirth., Jana Chaloupková., 3 tabulky, 2 grafy, Poznámky na str. 39 (2), Biografická poznámka o autorce článku na str. 39, Obsahuje bibliografii, and Resumé o klíčová slova anglicky na str. 30