There is a varying frequency of oral clefts between different ethnic groups and several European regions: however, global investigations on the incidence of oral clefts over longer periods in Germany do not exist, because there has been no continuous system of registering malformations. Such a registration system has been in existence in Magdeburg, with a population of about 1.5 million and a yearly birth rate of about 8000 children, since 1980. A very high rate of oral clefts was found in Magdeburg, mainly a cleft lip with or without a cleft palate, which is a prevalence of 18.5 per 10,000 births. Twenty-two percent of all children with oral clefts had additional malformations. At a rate of about 10%, heart defects were most frequently combined with oral clefts. A significant prevalence increase was recorded in 1988 and 1989. Exogenous influences are being considered as a joint cause for this increase because of the prevalence peaks of neural tube defects from 1987 to 1989.