Liver is the most common target for toxic injury. Toxic agents include chemicals such as carbon tetrachloride (CCl₄) and trichloroethylene. This study aimed to evaluate the effect of bone marrow cells (BMC) transplantation and/or fractionated low doses (0.5 Gy) gamma radiation on established liver fibrosis induced by CCl₄. BMCs of male albino rats were transplanted into 4-weeks carbon tetrachloride (CCl₄)–treated and/or fractionated low doses (0.5 Gy) gamma irradiated rats through the tail vein, and the rats were treated for 4 more weeks with CCl₄ (total 8 weeks). Histological and ultrastructural investigations revealed that both bone marrow cells transplantation and low dose (0.5 Gy) gamma radiation exposure with continuous CCl₄ injection had reduced liver fibrosis as compared with rats treated with CCl₄ alone.