A screening program for congenital adrenal hyperplasia (CAH) in Sapporo began in 1982, 7 years prior to the introduction of the national program. Since its inception, testing has involved the detection of 17-hydroxyprogesterone (17-OHP) in dried blood samples, using ELISA. Up to the end of March 1998, of 298,731 newborn screened, second samples were requested in 1,723 cases (0.6%). This number included 789 newborns who weighed less than 2,000 gm at birth. A total of 14 cases were diagnosed with 21-hydroxylase deficiency (21-OHD). "Salt-wasting type (SW)" outnumbered "simple virilizing type (SV)" by 11:3. The ratio of male to female was a converse. but unrelated, 3:11. Our study from 1982-1997 revealed that the incidence of 21-OHD in Sapporo City was 1:21.338, markedly similar to the worldwide incidence of 1:15,000. In order to improve the program, other type of analysis are also currently in use and under evaluation. These include highly sensitive HPLC analysis for 17-OHP and molecular analysis to identify some mutations associated with the 21-OHD gene (CYP21). These methodologies are very useful for the confirmation of information acquired from dried blood specimens.