Purpose: The association between fetal aberrant right subclavian artery (ARSA) and Down syndrome has beenknown for a long time. The aim of our study was to determine the incidence of ARSA in our population and itsassociation with Down syndrome and congenital heart diseases (CHD).Materials and methods: Between 2015-2018 years, fetal echocardiography was performed in 3150 pregnantpopulation at a tertiary referral center for prenatal diagnosis. The presence of ARSA was verified by visualizationof the transverse 3-vessel trachea view by color Doppler sonography during fetal echocardiography. Thefrequency of ARSA and its correlation with Down syndrome were investigated in our study.Results: Among the 3150 patients, an ARSA was detected in 42 fetuses (1.3%) and isolated ARSA wasdetected in 36 fetuses (1.14%). Of nine fetuses with Down syndrome, ARSA was positive in two (22.2%). ARSAwas positive in only one of the fetuses with CHD (4.1%). The positive likelihood ratios of isolated ARSA for Downsyndrome and CHD were 0.73 and 3.81, respectively.Conclusion: In our case series, prenatal detection of ARSA does not appear to be a strong marker alone ofDown syndrome and the isolated ARSA shows a weak association with CHD.