The paper focuses on the intergenerational and intragenerational transmission of religion in the Czech Republic. The authors start from the general statement that self-reported religious a liation in Czech society continued to decline during the second half of the 20th century. This trend has usually been explained by secularization theory and by speci cs of Czech social history, especially with regard to the anti-religious policies of the Communist regime. In their analysis of data from ISSP 2008 – Religion, the authors aim at a more detailed inquiry into the factors responsible for the decrease in self-reported religiosity in the Czech Republic. The results show that the key factor lies in de-conversion, which is not compensated su ciently by conversion in either type of transmission, inter- or intragenerational., Antonín Paleček, Roman Vido., and Obsahuje seznam literatury