Serum measurements of thyroid hormones (T4-TSH) in cord blood could detect hypothyroidism in the neonatal period.Traditionally, screening strategies for the detection of CH were either a primary TSH / back up T4 method or a primary T4 / backup TSH method. A third strategy uses TSH plus T4 as the primary test. Changes in TSH levels in response to T3 and T4 blood levels forms the basis of screening for CH. Blood samples were collected in a sterile container drawn from a 15 - 20 cm length of the umbilical cord incised while severing it at the time of birth of the baby. Thus, a mixed cord blood sample (1.5 ml) including both from the umbilical artery and vein was obtained. T3, T4 and TSH were estimated by competitive immunoassay by using VITROS Total T3 and T4 Reagent Pack and the VITROS Immunodiagnostic Products TSH30 Reagent Pack. It was observed that mean value of T3, T4 and TSH was 72.69±13.12 ng/dl, 9.01±2.227 µg/dl and 8.64±6.195 mIU/l respectively in cord blood.Mean value of T3, T4 and TSH was 82.40±11.76 (ng/dl), 11.55±3.596 (µg/dl), and 2.98±2.191 (mIU/l) respectively in day 3 venous blood sample.Comparison and co-relation between T3, T4 and TSH levels between cord blood and day 3 venous sample was statistically significant, with p-value 0.001 as very highly significant..