The aim of this study was to investigate the accuracy of the Nuchal translucency (NT) measurement between 11 and 13 weeks and 6 days of gestation as a marker to screen for congenital heart defects (CHD). 100 pregnant female patients who had come for routine antenatal scan were studied in a time period of 6 months in their later first trimester (12 to 14 weeks) and the nuchal translucency was measured. NT measurement was performed using philips affinity 70g machine in the first trimester examination. The cases were followed up to one month postpartum to assess the presence of CHD.A progressive increase in the prevalence of CHD according to the NT values obtained in the examination was observed. The relationship between NT size and major cardiac defects was analyzed, and it was found that the incidence of cardiac defects increased along with NT size. In sample, the use of NT as a screening method for CHD showed a low sensitivity –of 20% when the 95th percentile was used as the cut-off point. However, the specificity of the method was high - 99.4% for the 4.0 mm cut-off point. The negative predictive value was always above 99% at the different cut-off points. Evaluation of the nuchal translucency should be considered during the first trimester ultrasound as increased NT is associated with a spectrum of fetal abnormalities and chromosomal defects.