The objective was to evaluate the rates of congenital malformation in children born in a population living around a smelter and to employees at the smelter, in a community in northern Sweden. By means of record linkage of the birth register and various registers of congenital malformations, a retrospective study of a birth cohort according to place of parental residence and employment was carried out to assess rates of congenital malformation occurring between 1973-1990. Neither a general, nor specific, significantly increased risk of congenital malformation was seen in the 2724 children born to women living close to the smelter or to employees of the smelter compared with the 15191 children in the reference population. No increased risk could be ascertained although there are reservations concerning the small sample size of the study group.