Abstract: The role of Nigella sativa (N. sativa) in the prevention of liver damage induced by carbon tetrachloride (CCl4) was investigated. Twenty five Wister albino rats were allocated into 5 groups named as A, B, C, D and E. Group (A) was given paraffin oil, group (B) was given dimethylsulfoxide, group (C) was given CCl4 to induced hepatotoxicity, group (D) and (E) were administered with CCl4 together with 250 and 500 mg kg-1 body weight (b.wt.) methanolic extract of N. sativa which was dissolved in dimethylsulfoxide, respectively. Rats were scarified after 10 days. There was an increase in the body weights of the control groups A and B at a rate of 2%. However, the body weights in group C, D and E were reduced by 10.3, 9.3 and 10.3%, respectively. There were no significant changes in the blood picture between the control groups and the treated ones on day 10. The mean plasma ALT, AST and ALP were found to be significantly higher in both CCl4 and N. sativa treated groups compared to the controls, but the increase was less in the groups which were treated with N. sativa methanolic extract with CCl4. The bilibrubin concentration was raised from 0.2 to 0.7 in the group treated with CCl4 and to 0.6 and 0.4 in those treated with 250 and 500 mg kg-1 b.wt. of N. sativa methanolic extract. The histopathological changes in the livers of the group treated with CCl4 exhibited severe centrilobular vacuolation and congestion but in the groups treated with 250 and 500 mg kg-1 b.wt., these changes were to a lesser extent.