This study aimed to determine the relationship between the fetal sex preferences of pregnant women and fathers and their prenatal levels of attachment to the fetus. This analytical and cross-sectional study was carried out with 152 married couples between 07/01/2022 and 02/01/2023. The study data were collected using information forms prepared for pregnant women and prospective fathers, the Maternal-Fetal Attachment Inventory (MFAI) for pregnant women, and the Paternal Antenatal Attachment Scale (PAAS) for prospective fathers. In the study, it was determined that attachment related to some individual and fetal sex characteristics of pregnant women and prospective fathers was correlated and that male fetal sex increased the levels of prenatal attachment in both pregnant women and prospective fathers (p