Calcium, magnesium, copper and zinc in the maternal and umbilical cord serum were measured in 106 patients suffering from pregnancy-induced hypertension (PIH) and 106 controls. Mean maternal serum values of Ca, Mg, Cu and Zn in the PIH group were 2.460 mmol/L, 0.839 mmol/L, 35.094 mol/L and 8.408 mumol/L,respectively and were compared with the corresponding Values of 2.765 mmol/L, 0.834 mmol/L, 31.486 mumol/L, and 9.657 mumol/L in the controls. The Ca and Zn levels were lower and Cu higher in the PIH group (P less than 0.05 or P less than 0.01). No significant difference was found in the four elements in umbilical cord serum between the PIH cases and controls, indicating that the fetus can maintain an adequate Ca, Mg, Cu and Zn homeostasis even in pregnancy-induced hypertension. However, PIH cases had a lower Ca level in maternal serum than in umbilical cord serum. This study suggests that maternal serum Ca, Cu and Zn are related to PIH, and Ca might have a causal role in the development of PIH.