Application of immunohistochemical methods has greatly contributed to diagnostic thyroid pathology, especially to the diagnosis of thyroid tumors. These techniques can demonstrate specific markers for follicular and C (parafollicular) cells and their tumors. Therefore, they facilitate defining the spectrum of thyroid tumors, and also are useful for the distinction between tumors of different histogenesis. In this paper, we reviewed thyroid specific proteins and compounds as immunohistochemical markers, i.e. thyroglobulin (TG), thyroxine (T4), triiodothyronine (T3), thyroperoxidase (TPO), TSH receptor (TSHR), Nail symporter (NIS), thyroid transcription factor-1 (TTF-1), and calcitonin. In addition, we also reviewed intermediate filaments and other proteins having a considerable diagnostic value in thyroid tumor pathology.