The Down Syndrome (47,XY,+21) is a rare chromosome abnormality. The aim is to describe the clinical features and diagnosis of rare event. A newborn boy was born to our unit at TS Misra Medical College & Hospital. He was born at 37 weeks' gestation via caesarean section due to Latent Labour. The boy was 49 cm in length, 2345 Gram in weight with head circumference of 31 cm. He had the characteristic features, including flat facial profile, flat nasal bridge, short thick neck, low-set ears, high palate, simian crease, epicanthal fold, slanted palpebral fissures, sandle gap. Hypotonia was noted as well. The Doppler echocardiography showed PDA defect (3 mm) with left to right shunt, and mild tricuspid regurgitation, with right atrium and right ventricle mildly enlarged. Cytogenetic analysis confirmed a karyotype of 47,XY,+21. Down syndrome is a rare disease. Karyotyping should be performed for all patients with suspected Down syndrome and in even babies born from young parents.