Background: Congenital heart diseases (CHDs) account for a third of all major congenital abnormalities in children; nearly 1,80,000 children are born with heart defect each year in India. Approximately, 10% of present infant mortality in India may be attributed to CHD alone. Such high mortality is due to laying less emphasis on its prenatal diagnosis by fetal echocardiography. This study was done with objectives to find out the incidence of CHD in high risk cases and its correlation with karyotype and also evaluating the diagnostic accuracy of fetal echocardiography. Methods: Fetal echocardiography was performed in 142 high risk cases who attended antenatal clinic of Institute of Medical Sciences (IMS), Banaras Hindu University (BHU), Varanasi between July 2014 to June 2016 with maternal/fetal risk for CHD (maternal diabetes mellitus, collagen disorders, teratogen exposure, maternal TORCH infection, in vitro fertilization [IVF] conceived pregnancy, familial history of CHD, abnormal fourchamber view, monochorionic twins). Results: The incidence of major CHD was 28/1,000 live births and 56/1,000 live births for minor CHD in high risk group. Ventricular septal defect (16.6%) and hypoplastic left heart syndrome (16.6%) were the most common CHD detected. Family history of CHD increases the risk significantly. Fetal echocardiography was 75% (46.77-91.11, 95% confidence interval [CI]) sensitive and 94.5% (89.22-97.35, 95% CI) specific, with 92.91% (87.44-96.1, 95% CI) diagnostic accuracy. It was seen that 16.6% cases of CHD had aneuploidy detected on karyotyping (trisomy 21 and trisomy 18). Conclusion: Fetal echocardiography is highly sensitive and specific, when done by an experienced operator. Prenatal diagnosis of CHD and planned delivery in a cardiac facility had satisfactory immediate outcomes.