The enhancement of glucose metabolism in neoplastic cells is mediated by the overexpression of key glycolytic enzymes and glucose transporters (GLUTs). In particular, an increased expression of hypoxia-related GLUT1 and GLUT3 has been found in a variety of malignancies. The aim of this study was to examine the expression levels of GLUT1 and GLUT3 in benign and malignant thyroid tumors, as well as in non-neoplastic lesions. Analysis of the mRNA expression levels of solute carrier family 2, member 1 (SLC2A1) and solute carrier family 2, member 3 (SLC2A3) (genes coding GLUT1 and GLUT3, respectively) was performed by the real-time PCR method with fluorescent probes. GLUT1 and GLUT3 protein expression levels were determined in thyroid specimens by immunodetection after separation of proteins on 10% polyacrylamide slab gels and electrotransfer onto Immobilon-P membranes. The majority of papillary carcinoma samples showed a higher expression of GLUT1 and GLUT3 in comparison with follicular carcinoma cases and non-neoplastic thyroid lesions. A tendency towards an increased expression of GLUT1 and GLUT3 was observed in papillary carcinoma cases with more advanced disease stages. Moreover, a significant correlation was noted between the hypoxia-related GLUT1 and GLUT3 expression determined by both methods. In conclusion, our findings suggest that GLUT1 and GLUT3 play an important role in the pathology of thyroid glands.