The activity of superoxide dismutase (EC 1.15.1.1) was not greatly affected by zinc deficiency in maternal or foetal (20 d) rat livers, although in the latter tissue it did appear to be slightly raised by Zn depletion when compared with pair-fed control animals. 2. Enzyme activity was significantly higher in livers from all foetuses after administration of aqueous ethanol at 100 or 200 ml/l to the dams during pregnancy. 3. Plasma Zn levels were significantly increased in Zn-deficient dams after ingestion of alcohol during pregnancy.