Objective: the current study was designed to assess the therapeutic effect of bone marrow-derived mesenchymal stem cells (BMSCs) on parotid glands after streptozotocin induced diabetes in rats. Materials and Methods: 36 Sprague-Dawley rats were divided into 3 groups, 12 rats each. Group I: the animals received 0.1 M sodium citrate buffer intraperitoneally, the vehicle of streptozotocin. GroupII: diabetes mellitus was induced by single intraperitoneal injection of 60 mg/kg of streptozotocin (STZ) dissolved in 0.1 M sodium citrate buffer. Group III: one day after diabetes induction, simgle dose of 2×106 BMSCs suspended in 0.5 ml of phosphate buffer solution (PBS) was injected via intraglandular route. Animals were sacrificed at 7 or 14 days after BMSCs injection, then histological and immunohistochemical studies were done. Result: the experimental stem cell treated group showed better histological features and increased PCNA proliferation more than the untreated group. Conclusion: bone marrow derived stem cell is considered as relatively successful method for the treatment of diabetic induced salivary gland dysfunction.