Background: Stem cell therapy holds a great promise for the repair of injured tissues and organs, including the kidney.  Objective:  Study the possible role of bone marrow derived mesenchymal stem cells (BM MSCs) in regeneration of kidney tissue in acetaminophen-induced renal failure (RF).  Material and Methods:  Twenty four adult male albino rats of local strain were chosen as an animal model for this study. They were divided into control, RF rats, RF received culture media and RF received BM MSCs in a dose of one million cells / rat by intravenous injection.  Mesenchymal stem cells were separated from rat bone marrow, being identified by their morphology and immunophenotype (CD29, CD45 and CD90) by flow cytometry. BM MSCs were labeled with PKH26 dye before injection. RF was induced by oral administration of acetaminophen. At the end of the experiment (24 days), blood samples were obtained for serum creatinine and urea. Animals were sacrificed; kidneys were obtained for histopathological examination and measurement of tissue levels of malondialdehyde (MDA) and glutathione peroxidase (GPx).  Results: BM MSCs were successfully separated from bone marrow, being identified as mesenchymal stem cells showing plastic adherence properties and fibroblastoid shape. The cells showed +ve expression of CD29 and CD90, -ve expression of CD45 proving that it is mesenchyml cells not hematopoitic cells. Acetaminophen showed significant increase in serum creatinine, urea and tissue MDA. Also, there was significant decrease of tissue GPx. BM MSCs showed significant decrease in serum creatinine, urea and tissue MDA in addition to significant increase in tissue GPx. Histopathological examination revealed regeneration of the damaged kidney tissue and restoration of normal architecture of BM MSCs-treated group in comparison with RF group. Conclusion: BM MSCs have a curative role in regeneration of kidney tissue in acetaminophen-induced renal failure.