This study was carried out to determine the frequency of congenital heart defects, cholelithiasis, hypothyroidism and leukemia in 31 children with Down syndrome. Twenty children (71.4%) had congenital heart defects. Ultrasonography was performed on 29 and two of these (6.9%) had cholelithiasis. Tests for hypothyroidism in 24 children identified hypothyroidism in three (12.5%). Leukemia was diagnosed in three children (10%).(one with congenital, two acquired). One patient with congenital hypothyroidism underwent surgery on the third day of life because of annular pancreas and duodenal atresia.