Background: Diabetes mellitus (DM) is metabolic disorder affects different body organs. Insulin is mandatory for DM management. Bone marrow-mesenchymal stem cells (BM-MSCs) are characterized by their anti-diabetic effect. Objectives: To explore the effectiveness of BM-MSCs versus insulin on circumvallate and foliate papillae of diabetic rats. Materials and methods: 56 male albino rats were divided into: Control group (Gp 1): rats received no drug. Diabetic group (Gp 2): rats received a single intra-peritoneal injection of Streptozotocin (STZ) (40mg/kg). BM-MSCs treated diabetic group (Gp 3): After diabetes confirmation; rats were given a single intravenous injection of BM-MSCs through tail vein. Insulin treated diabetic group (Gp 4): After diabetes confirmation; rats received subcutaneous injection of insulin (5IU/kg/day). After 4 weeks, half of the tongue specimens were processed and examined by light microscope. While the other half were examined by scanning electron microscope. Results: Circumvallate and foliate papillae of Gp 2 showed marked histological and morphological alterations. While in Gps 3 and 4, the papillae showed noticeable improvements, being more obvious in insulin treated one. Conclusions: BM-MSCs administration could help in reducing the damaging effects of DM on circumvallate and foliate papillae. Insulin therapy caused more efficient improvements in diabetic rats than BM-MSCs.