Reproductive behaviour in the Czech Republic and the Slovak Republic has undergone several major transformations in the 20th and early 21st century. Over a period of more than 100 years, the character of fertility and mortality has changed several times in a significant way.
The aim of this paper is to analyze the development of natality, fertility and mortality in both countries in a long-term aspect and to point out the main shifts in demographic reproduction since the establishment of Czechoslovakia to the present.