Abstract: This study was carried out to investigate the effects of ethanolic leaf extract Annona muricata (soursop) on N,N-dimethylnitrosamine (DMN)-induced liver fibrosis in rats. Four groups of Wistar albino rats (12 rats/group) were used for the study. One group received intra-peritoneal injection of 10mg of DMN/kg body wt. thrice a week (on the first three days) for 14 days, in addition to the extract at a dose of 200mg/kg body wt. given by gavage. A second group received the same dose of DMN but without extract, while rats in the third group were administered the same dose of extract without DMN. Members of the fourth group were given physiological saline (vehicle), and served as controls. After 14 days, the rats were sacrificed by cardiac puncture. Blood samples were collected from the ocular vein, and the sera were analysed for aspartate transaminase, AST; alanine transaminase, ALT and alkaline phosphatase, ALP; while collagen, malondialdehyde, MDA; reduced glutathione, GSH, superoxide dismutase, SOD and catalase, CAT levels were assayed in liver tissue. All assays were done using standard methods. Liver sections were also fixed in formol-saline and subjected to histological analysis. DMN administration resulted in significant increases in serum AST, ALT and ALP; and in liver MDA and total collagen content (P 0.05). On the other hand, liver SOD and CAT activities were significantly reduced by the DMN treatment. Histological examination of liver sections from the DMN rats showed severe degenerative changes such as congestion, haemorrhagic necrosis and deposition of thick collagen fibers. These biochemical and histological changes were reversed significantly by the Annona muricata leaf extract.These results suggest that Annona muricata leaves may reverse hepatic fibrosis probably through maintenance/restoration of liver antioxidant status.