The heat shock proteins (HSPs) 70 and HSP 27 expression in patients with non-small cell lung cancer (NSCLC) was studied and the relationship between HSP 70 and HSP 27 with the clinicopathological features of NSCLC was investigated. The expression of HSP 70 and HSP 27 was detected in tumor tissues from 60 patients with NSCLC by S-P immunohistochemistry. The findings were analyzed in combination with the histological types, histopathological differentiation, lymph node metastasis, patients’ clinical stages, smoking history and gender. The results showed that of the 60 NSCLC tissue specimens studied, the immunoreactivity of HSP 70 and HSP 27 was detected in 47 (78.3 %) and 43 (71.7 %) specimens, respectively. A positive correlation was found between the overexpression of HSP 70 and HSP 27. The histopathological differentiation, lymph node metastasis, clinical stages and smoking history were correlated to the expression of HSP 70, but not to the expression of HSP 27. No statistical significance was observed in histological types and gender with respect to both HSP 70 and HSP 27 expression. It is suggested that the HSP 70 expression is a powerful and significant prognostic indicator and is related to histopathological differ entiation, lymph node metastasis, patients’ clinical stages, smoking history, whereas HSP 27 expression is not.