The clinical features of congenital hypothyroidism are often subtle and many newborn infants remain undiagnosed at birth. This is due in part to passage of maternal thyroid hormone across the placenta providing a protective effect, especially to the fetal brain and masking the clinical signs. Also, even the most common forms of CH have some moderately functioning residual thyroid tissue making clinical diagnosis difficult. TSH was estimated within 24 hours by electrochemiluminescence immunoassay ‘ECLIA’ on elecsys 2010 analyser. All babies wherein the cord TSH was found to be over 20mIU/L were intimated within 24hrs of the test. A second venous blood sample from these babies for serum T4 and TSH estimation was collected between 2- 4 day of life. Of the 1037 neonates whose cord blood samples were analyzed 32 neonates had TSH values more than 20 mIU /L. On re estimation of TSH and T4 values more than 72 hrs later all cases who were found to have higher TSH values in cord blood had age appropriate TSH and T4 values. 23 neonates whose cord samples could not be collected during delivery or samples were hemolysed, serum TSH from venous samples collected after 72 hrs of life were found to be normal.