Analysis of prenatally diagnosed sex chromosome aneuploidies and disorders of sex development (DSDs). This study includes a retrospective data analysis of 46 prenatally detected sex chromosome aneuploidies and one case of 46,XY DSD diagnosed during an 11-year period (2002–2012) at our department. Of the 46 sex chromosome aneuploidies, 29 cases (63.0%) were in the group of a selected population of women according to abnormal first-/second-trimester ultrasound and 17 (37.0%) cases in an unselected population of women who underwent fetal karyotyping because of advanced maternal age. The most common aneuploidy was Turner syndrome in full and mosaic form (50%). Complete androgen insensitivity syndrome was diagnosed in the case of 46,XY DSD. Sex chromosome aneuploidies must be taken into consideration if, in the first or second trimester, abnormalities are revealed on ultrasound, mainly Turner syndrome in full or mosaic form and 47,XYY.