Delayed diagnosis and treatment of congenital hypothyroidism causes severe mental deficiency in children. Therefore, most of the European countries have introduced neonatal thyroid screening by TSH measurement in neonates during the first week of life. We have introduced TSH screening since 2002. Large nurseries from Skopje region, Bitola and Prilep are taking blood from the hill of neonates on special filter paper at the day of discharge, after 48 hours after birth. Filter cards are then transported to the Genetic laboratory at the Pediatric clinic within a week. During 4 years we have screened 37091 neonates from 5 nurseries covering 35% of all births in Macedonia. Method used for TSH screening was DELFIA. Cut of value for TSH in our laboratory is 15 µU/ml. Twelve children with neonatal hypothyroidism were detected through high neonatal TSH. The incidence was 1: 2649. Diagnosis of congenital hypothyroidism was confirmed by RIA method for precise measurement of TSH and ultrasound check up of the thyroid gland. Treatment of the disease with thyroxin supplementation was introduced at 9 days average (4-17 days after birth). Treated children have normal growth and development. Laboratory for thyroid screening is internationally recognized and blind tests are sent at 6 months intervals. The coverage of neonates is 98%. TSH values in the range 5-15 µU/ml are detected in 3.6% of the neonates confirming that Macedonia is free of iodine deficiency. Neonatal thyroid screening is necessary for timely diagnosis and treatment of children with congenital hypothyroidism. From 2005, neonatal thyroid screening has been introduced in the preventive programs for the Republic of Macedonia and will cover all neonates.