Purpose: This study aimed to evaluate the potential effect of Bone Marrow Derived Mesenchymal Stem Cells (BM-MSCs) in reducing the complication of hypothyroidism induced by Carbimazole through histological examination of the tongue. Material and Methods: 30 adult male albino rats were used and divided into three groups: Control group (GI) consisted of 10 rats allowed to access freely balanced diet and freshwater supply throughout the experimental period (8 weeks), Hypothyroid group (GII) in which 10 rats received carbimazole dissolved in distilled water with a dose of 5 mg/250g body weight/day by intra-gastric intubation for 5 weeks to induce hypothyroidism and BM-MSC group (GIII) in which 10 rats received carbimazole as in GII for 5 weeks and after confirmation of hypothyroidism received a single intravenous injection of BM-MSCs (1× 10 6 cells) through tail vein. All rats were sacrificed; tongue was dissected and processed for hematoxyline & eosin and fluorescent microscopic evaluation. Results: Tongue papillae of GII showed marked morphological and histological alterations including hyperchromatic nuclei, multiple vacuolation among the cells and apparent decrease in the keartohyaline granules' content. Moreover, the connective tissue (C.T.) core appeared loose with inflammatory cell infiltrate and numerous congested blood vessels. On the other hand, the papillae in BM-MSCs treated groups showed apparent improvement in their architecture. Conclusion: Hypothyroidism has degenerative effects on tongue papillae.Administration of BM-MSCs reduces the deleterious effects of hypothyroidism on the papillae.