Objective: We aimed to evaluate myocardial performance in fetuses with increased nuchal translucency. Method: Cases with increased NT without any associated structural anomalies were enrolled in this study. The study group consisted of 53 pregnancies complicated with thickened NT > 3.5 mm. Forty-six gestational age-matched pregnant women whose fetuses had normal NT thickness were enrolled in the study as the control group. The TEI index was evaluated before performing CVS in the group with an increase in NT. Karyotype analysis was performed via CVS in all patients with increased NT. In both groups, detailed fetal sonographic examinations, including fetal echocardiograms, were performed between 18 and 24 weeks of gestation. Results: The differences between normal and increased NT groups in terms of isovolumetric relaxation time (IRT), ejection time (ET), and myocardial performance index (MPI) variables were found to be statistically significant (p values of 0.023, 0.004, and < 0.001, respectively). For IRT and MPI variables, the median values of the group with an increase in NT were found to be significantly higher than that of the normal NT group, whereas the median value of the ET variable of the group with increased NT was significantly lower than that of the normal NT group Conclusion: The MPI significantly increased in the group with increased NT, but no difference was observed between those with and without Down syndrome. This suggests that increased NT is caused by cardiac dysfunction, whether or not Down syndrome is present.