Background: Prenatal diagnosis is an indispensable part of prenatal care today. Many mothers decide to undergo prenatal screening for Down syndrome, to better prepare for the life of a child with Down syndrome or have an abortion in case of determined high probability. Research has shown that Western European countries have significantly reduced the rate of births of children with Down syndrome through the widespread use of prenatal diagnostics. Aim: To examine the differences towards the attitudes in prenatal diagnosis of Down syndrome between mothers from Croatia compared to mothers from Bosnia and Methods: The research was conducted in the period from January to April 2023 on a sample of mothers aged 18 to 45 who lives in Croatia and Bosnia and Herzegovina. A total of 418 respondents participated in the research via an online questionnaire, 203 of them residing in Bosnia and Herzegovina and 215 respondents from Croatia. The questionnaire examined 11 attitudes about prenatal diagnosis and screening, attitudes about religiosity and worldview, and socio-demographic characteristics. The used questionnaire was taken from the NOBAS (Norwegian Bioethics Attitudes Survey) study. Results: In the end, the analysis was performed on the data obtained from 406 mothers, with 207 (51%) of them coming from Croatia, and 199 (49%) from Bosnia and Herzegovina. After the obtained results, the first hypothesis was partially confirmed. A statistically significant difference was found in 4 out of 11 statements about prenatal diagnosis and screening for Down syndrome between mothers from Croatia and mothers from Bosnia and Herzegovina. Conclusion: The question of prenatal diagnosis of Down syndrome is important question for the future as well as the present of bioethics in Croatia and Bosnia and Herzegovina. Therefore, it is important to pay attention to this problem and continue conducting research of the same or similar character.