Registration of congenital malformations began in 1979 in the French department of Bas-Rhin. The results of the first 10 years of functioning of this register are presented after description of the objectives and methodology used. 131,760 consecutive births were analysed: 2.66% of infants presented with malformations. The most frequent malformations consisted of congenital heart defects (11.6%). The increase in incidence of congenital malformations was not the result of an absolute increase in malformations but to improvement of prenatal and postnatal diagnosis allowed by the technical progress in this field. In utero diagnosis of congenital malformations, especially of multiple malformations, was more and more often performed.