Introduction: Structural fetal abnormalities occur in approximately 2-3% of all pregnancies, prenatal diagnosis, karyotyping is considered the gold standard because of its greater diagnostic accuracy to identify structural abnormalities and diagnose the most frequent aneuploidies. However loss or gain of genetic material is better studied by other techniques like array comparative genomic hybridization. Aims: To find the incidence and type of abnormal karyotype in foetuses with major congenital malformations detected on prenatal ultrasound. Materials and methods: All the pregnant patients with major congenital anomaly on prenatal test between January 2018 to October 2018 and total 47 patients are included in study. Routine ante natal investigations were done. Results: Abnormal karyotype was found in 28.5% (12/42) of samples. Numerical Abnormalities were seen in 6 patients (Trisomy 21 n=5 Monosmy 1). In our series the commonest anomaly was Trisomy 21 (5/12, 41% of patients). 92.9% with structural neural abnormalities had a normal karyotype. Eleven patients had structural cardiac abnormalities of which 6 (54.5%) had an abnormal karyotype. Fifty percent of patients with renal agenesis and 40% of patients with skeletal abnormalities had abnormal karyotype. Conclusion: Screening test should be done all pregnant patients irrespective of age and risk factors to identify the abnormal karyotype early in pregnancy which is found in significant proportion of foetuses with anomalous finding on prenatal ultrasound.