We assessed the anti-fibrotic effects of methanolic black bean extract antioxidants in a carbon tetrachloride (CCl4) liver injury model in rats. Experimentally intoxicated animals received CCl4 for eight weeks, the reference and test groups received daily intragastric quercetin or daily intragastric black bean extract. Liver fibrosis was assessed and quantified using morphometric analysis. Expression of fibrosis related genes was measured by real time RT-PCR. Qualitative and quantitative histological analysis showed that administration of 70 mg/kg b.w. of black bean extract reduced hepatic fibrosis index by 18% compared to positive controls (P 0.006), as a result of a decrease in type I (44.3% less, P 0.03) and type IV (68.9% less, P 0.049) collagen gene expression compared to CCl4-injured and Quercetin treated rats. In conclusion, we provide evidence that this methanol black bean extract ameliorates liver fibrosis and types I and IV collagen gene expression, in the animal model used. Practical applications: The compounds contained in this black bean extract exhibited strong antifibrotic effects in the CCl4 chronic liver injury model used; considering that this compounds are contained in a leguminous that has been used in human diet for a long time, their toxic potential should be very low, and this characteristic should favor their potential use in some other chronic or degenerative states that include an increase in inflammation and oxidative burst in their pathogenesis. Another possible application of this kind of extract could be its use as an antimicrobial or even antiparasitic therapeutic agent, although it is purely speculative.