Growth factors and the receptors play an important role in the regulation of the growth and development of mammalian cells. In particular, epidermal growth factor is a polypeptide with potent mitogenic activity that stimulates proliferation of various normal and neoplastic cells through the interaction with its specific receptor(EGFR). EGFR has been described as a parameter of poor prognosis in many human neoplasms such as breast, bladder, and vulvar cancers. The objectives of this study are the evaluation of the expression of EGFR and cell cycle analysis in the head and neck squamous cell carcinomas(SCC), and the evaluation of the correlation between clinico-patholgic features and expression of EGFR and S-phase fraction. 37 head and neck squamous cell carcinoma specimens were evaluated for expression of EGFR by Western blot analysis and S-phase fraction by cell cycle analysis using the flow cytometry. The obtained results were as follows : 1. The expressions of EGFR were observed in 20 specimens(54%) among 37 head and neck SCC specimens. In case of oral SCC, 15 specimens(56%) out of 27 specimens were observed, and in case of nasopharyngeal SCC 5 specimens(50%) out of 10 specimens. 2. There was no correlation between clinical features(location, stage) of head and neck SCC and expression of EGFR (p>0.05). 3. There was a significant correlation between histo-pathological differentiation of head and neck SCC and expression of EGFR (p<0.02). 4. There was a significant correlation between expression of EGFR and S-phase fraction of cell cycle in the head and neck SCC (p<0.05). The above results suggest that expression of EGFR and S-phase fraction of cell cycle are adjunctive prognostic marker in the head and neck squamous cell carcinomas.