As the prevalence of developmental disorders (DDs) has increased, many OECD countries provide a national screening examination for early detection and intervention for DDs. This study examined effects of the National Health Screening Program in Korea. 65,334 children (39%) were DD-screened and 35,466 children (21%) received a false negative among the 167,050 study subjects. The DD-screened rate had increased from 3208 (27.2%) in 2008 to 8471 (47.3%) in 2012, then decreased to 5544 (29.8%) in 2017. Changes in the false negative rates increased from 2.7% in 2008 to 23.8% in 2017 were one of the most influential factors in these fluctuations. The DD-screened rate was influenced by demo-geographic and economic factors as well as by age-related characteristics of the subconditions.