Background: Liver fibrosis and cirrhosis are major causes of morbidity and mortality worldwide. Precise determination of liver fibrosis stage is crucial for the choice of optimal therapies. Liver biopsy is the most accurate method used to evaluate progression of chronic liver diseases but it has several complications. Recently many non-invasive markers (NIMs) for assessing liver fibrosis have been developed. Aim: This study was done to evaluate invasive method and non-invasive methods in assessment of CCl₄ induced liver fibrosis and the reversibility of liver fibrosis by angiotensin receptor blocker (Losartan). Methods: Forty-two adult albino rats were divided intoControl group (n =12), CCl4 treated groub (n = 18) and Losartan treated group (n=12). At the assigned times, serum SGPT and SGOT were assayed by thecolorimetric method and serum tissue inhibitor metalloproteinase 1 (Timp1) by Elisa. Livers of rats were stained with H & E for histopathological examination, Masson trichrome and Sirius red for liver fibrosis, and Immunostaining for Timp1. Results & Conclusions: The results concluded that non-invasive methods can express the difference that occur in liver fibrosis but it cannot estimate its degree so it cannot replace the liver biopsy. Further research could identify other promising non-invasive methods.