Background: Hepatoprotective effects of Fumaria parviflora have been approved in pharmaceutical and chemical toxicity models. Given the importance of the vincristine-induced hepatotoxicity during chemotherapy, the aim of this study was to investigate the potential hepatoprotective effects of F. parviflora extract on vincristine induced toxicity in adult male rats. Materials and methods: In this experimental study, the rats (n=42) were divided into 7 groups: 1) Sham group, 2) vehicle group, 3) vincristine group (VCR) (0. 5 mg/kg, i. p. ), 4) F. parviflora extract (300 mg/kg, p. o. ), 5) F. parviflora extract (500 mg/kg, p. o. ), 6) Pretreatment group: F. parviflora extract (300mg/kg for 10 days, p. o. ) + VCR (0. 5 mg/kg, i. p. ) on 9th and 10th days of the experiment, and 7) Pretreatment group: F. parviflora extract (500mg/kg for 10 days, p. o. ) +VCR (0. 5 mg/kg, i. p. ) on 9th and 10th days of the experiment. Serum values of AST, ALT, ALP and malondialdehyde (MDA) were measured. Data were analyzed by one way ANOVA using prism software. Results: F. parviflora extract with dose of 500 mg/kg markedly decreased ALT hepatic enzyme level caused by vincristine (P<0. 01). In addition, the dose of 300 mg/kg could not decrease the elevated liver enzymes, including ALP, ALT and AST and also MDA levels. Conclusion: Hepatoprotective effects of F. parviflora extract were not considerable in pretreatment groups.