Diabetes constitutes a worldwide epidemic affecting all ethnic groups. Stem cell therapy provides an effective way to regenerate insulin-producing cells lost during the disease. Accordingly, we isolated and compared the differentiation ability of nestin rich bone marrow mesenchymal stem cells (MSCs) into insulin producing cells (IPCs) with the nestin poor counterpart. The purity of the isolated populations was evaluated by immunofluorescence then, cells were differentiated into IPCs. At the end of differentiation, cells were evaluated by expression of pancreatic endocrine genes, immunofluorescence as well as the release of human insulin and c-peptide according to increasing glucose concentrations that showed a significant difference. Under confocal microscope the mean percentage of IPCs was 14.3% for nestin rich MSCs while nestin poor MSCs showed 2.17 %. In conclusion, nestin positive cells is a sub-population of MSCs, capable of generating IPCs in higher percentage than its negative counterpart. Key words: Nestin; Mesenchymal stem cells; differentiation; insulin producing cells.