The aim of this study was evaluation of some specific markers of hematopoietic and mesenchymal stem cell and in mesothelial cells of peritoneum. In order to investigate the plasticity of Mesothelial Cells (MC), cell population from peritoneal dialysis fluid of early stage non-peritonitis male patients with 35-40 years old were first screened. Then they were analyzed by cell culture, flow cytometry and immunophenotyping for dominant markers such as CD45 and CD34 (as hematopoietic stem cell marker), HBME-1 (as mesothelial cell marker) and cytokeratin 18 (as an epithelial marker). Our results showed MCs possess some identical markers to mesothelial and epithelial cells. Also both mesenchymal (CD34ˉ) and hematopoietic (CD45+) stem cell markers were detected in these cells. This study could change the previously assumed plasticity of mesothelial cells as progenitor cells and lead us to the definition of a new expression of surface markers of MCS.