Six groups of male Wistar rats were treated as follows: in groups II, III and V liver damage was induced by CCl(4) (per os, 1590 mg/kg b.w.day) given 2 days a week for 6 weeks; group III was treated simultaneously with ethanol extract of Aquilegia vulgaris (100 mg/kg b.w.day) for 6 weeks; group V with silymarin, positive control, at a dose of 100 mg/kg b.w.day for 6 weeks; and groups IV and VI received only the extract or silymarin, respectively. Microsomal lipid peroxidation in the liver increased following CCl(4) treatment by 61-213% and was not changed significantly by the extract. The effect of silymarin was more pronounced, 19-52% decrease in the lipid peroxidation level. Hepatic glutathione was depleted by 22% in CCl(4)-treated rats. The extract tested did not change this parameter. The activity of antioxidant enzymes was significantly reduced after CCl(4) administration, by 42-63%. Co-administration of the extract or silymarin resulted in significant increase in these enzymes activity; however, the basal level was not reached. Hepatic hydroxyproline concentration was elevated over 5-fold in comparison with controls. Co-administration of the extract or silymarin decreased the level of hydroxyproline by 66% and 55%, respectively. Activity of serum hepatic enzymes was elevated in rats treated with CCl(4) by 47-8700%. Both the extract and silymarin reduced significantly these enzymes' activity. The extract caused a fall in bilirubin and cholesterol level in rats treated with CCl(4) by 42% and 17%, respectively. Histopathological examination revealed less-severe fibrosis in rats co-administered the extract or silymarin when compared to animals treated with CCl(4) alone.