Objective: Cell transplantation has tremendous interest as an approach to imporve cardiac disease. Various cell populations, such as embryonic stem cella, cord blood, and messenchymal stem cells, have been suggested as a source for replacement therapy. With regards to the limitations of using stem cells, transdifferentiation of the fully differentiated cells can be the other choice. In the present study, we investigated whether human peripheral blood cells could transdifferentiate into myocardium. Materials and Methods: Hhuman B lymphocyte (Raji) was used. Cardiomyocyte extract was prepared from adult mouse cardiomyocytees. The cells were treated with 5-aza-2-deoxycytidine and trichostatin A, permeabilized with stereptolysin O, and exposed to the mouse cardo myocyte extract. They were cultured for 10 days, 3 and 4 weeks. Immunohistochemistry and flowcytometry were preformed for cardiomyocyte markers. Results: Immunohistochemistry revealed that some cells expressed myosin heavy chain, alpha-actinin and cardiac troponin T after 3 and 4 weeks. Flowcytometry confrimed these data. After exposure to cardiomyocytes extract, some of the permeabilized and cardiac extract treated cells adhered to the plate loosely; however, the morphology did not changed. Conclusion: The lymphocytes expressed cardiomyocyte markers. However, this study showed that lymphocytes had the capability to be used in the future research as a source of cell for cell-therapy.