The purpose of this study was to investigate the effect of an iron-deficient diet on the hepatic glutathione (GSH) level, glutathione S-transferase (GST) activity and cytochrome P-450 (P-450) content in young female rats. Wistar-strain female rats (40-50 g in body wt.) were fed ad libitum with a normal diet (50 ppm Fe) or iron-deficient diet (8 ppm Fe) diet for 4 weeks. Compared to the control rats given the normal diet lower feed intake, weight gain, liver weight and hemoglobin concentration were found in those fed on the iron-deficient diet. In respect of the hepatic drug-metabolizing system, an increase in GSH level was observed together with the induction of P-450 content in the iron-deficient animals. The GST activity against three different substrates (1-chloro-2, 4-dinitrobenzene, 3, 4-dichloronitrobenzene and trans -4-phenyl-3-buten-2-one) was also higher in the iron-deficient rats.The data suggest that iron-deficient young female animals may respond differently to drugs and chemicals than their non-iron-deficient counterparts.