Effectiveness of Nigella sativa and Urtica dioica. in prevention of carbon tetrachloride-induced liver injury were investigated in this study. Sprague-Dawley rats were given carbon tetrachloride dissolved in olive oil intraperitoneally three times a week for 11 weeks. After liver fibrosis was developed, carbon tetrachloride was discontinued and rats were randomized in four groups. They were treated with Nigella sativa fixed oil (2 ml/kg), Urtica dioica fixed oil (2 ml/kg) or Nigella sativa (2 ml/kg) and Urtica dioica (2 ml/kg) per orally for four weeks. The control group was untreated. The animals were sacrificed and specimens were taken for biochemical and histopathological study at the end. Cessation of carbon tetrachloride allowed for partial recovery of liver tissue by autoregeneration in control group. Liver fibrosis was further progressed in all three treatment groups and resulted in cirrhosis in some animals. In Urtica dioica group alanine aminotransferase level was significantly higher compared to other groups. Serum indirect bilirubin levels were higher in Urtica dioica and Nigella sativa groups compared to control and Nigella sativa+Urtica dioica groups. Present study indicate that fixed oils of Nigella sativa, Urtica dioica and Nigella sativa +Urtica dioica did not show a therapeutic effect in experimental liver fibrosis in rats.