Lead acetate (300 mg/L) and/or cadmium acetate (10 mg/L) were administered as drinking water to pregnant Wistar rats from day 1 of pregnancy to parturition (day 0) or until weaning (day 21) to investigate the possible nephrotoxic effects of these metals. We also studied the possibility of toxicological interactions between both metals. Kidneys were used to determine the activity of several enzymes considered key to correct renal function: alkaline and acid phosphatases, Mg(2+)/Ca(2+)-dependent ATPase, and Na(+)/K(+)-dependent ATPase. The results showed a general decrease in the activity of these enzymes after treatment with the heavy metals; this fact suggests that lead and cadmium are able to impair renal function due to biochemical alterations, since ATPases are essential for reabsorption and secretion processes and phosphatases are involved in the differentiation of the proximal tubules. On the other hand, simultaneous perinatal administration of both metals seems to protect against the toxicity produced by cadmium or lead separately. It is not clear whether this is due to decreased absorption or increased sequestration or excretion.