Heat shock protein 27 (hsp27) is expressed by squamous cell carcinoma of the uterine cervix. Results from an earlier study by our group indicted that hsp27 may be a diagnostic marker for cervical intraepithelial neoplasia (CIN) and carcinoma. p16 expression is known to be elevated in intraepithelial uterine cervical cancer and grades 2 and 3 lesions (CIN2, CIN3), but has also been reported to be negative in 5-20% of cervical cancer and CIN lesions. The aim of our study was to confirm immunohistochemically the expression of hsp27 and p16 in cervical lesions. Formalin-fixed, paraffin-embedded cervical tissue specimens obtained between 2002 and 2010 were investigated for hsp27 and p16 expression. Positive staining was detected for hsp27 in 63% of normal cervical tissues, 47% of CIN1 lesions, 75% of CIN2 lesions, 92% of CIN3 lesions, and 100% of squamous cell carcinomas (SCC); the corresponding rates for p16 positivity were 29, 47, 67, 92, and 75%, respectively. Positive staining for both hsp27 and p16 was observed in 6% of normal cervical tissues and in 19% of CIN1, 18% of CIN2, 85% of CIN3, and 75% of SCC specimens. Hsp27 or p16 positivity had a sensitivity of 95.6 or 84.7% and a specificity of 37.2 or 70.5%, respectively, for the identification of CIN3 or SCC lesions; when both hsp27 and p16 were assessed, both the sensitivity and specificity were improved. In conclusion, both hsp27 and p16 immunohistochemistry is a useful tool for the diagnosis of CIN3 lesions or cervical SCC.