The R563Q mutation of the -subunit of the epithelial sodium channel (ENaC) is associated with hypertension in black and mixed ancestry (MA) men and women in South Africa. The frequency of the R563Q mutation in black and MA women with pre-eclampsia (n= 230) and in controls (n= 198) was studied. The R563Q mutation was found in 7.8% of the women with pre-eclampsia and in 2.6% of controls (P= 0.014). This remained significant if the black women were analysed separately (P= 0.031). We have demonstrated that a genetic variant of the ENaC is associated with pre-eclampsia. This has implications for understanding the pathogenesis and treatment of pre-eclampsia.