This study investigated the immunohistochemical staining characteristics of glutathione-S-transferase alpha, pi, mu, theta and p53 in non-small cell lung carcinoma and normal lung tissue from 50 patients. The relationships between expressions of the Glutathione-S-transferase isoenzymes and some clinicopathological features were also examined. Expression of glutathione-S-transferase pi, mu, alpha, theta and p53 was assessed by immunohistochemistry for primary lung carcinomas of 50 patients from the Sanitarium Education and Research Hospital, Ankara lung cancer collection. The relationships between expression of the glutathione-S-transferase isoenzymes, p53 in normal and tumor tissue by Student T test and the clinicopathological data were also examined by Spearman Rank tests. When the normal and tumor tissue of these cases were compared according to their staining intensity and percentage of positive staining, glutathione-S-transferase alpha, pi, mu, theta expressions in tumor cells was significantly higher than normal cells (p<0.05). There was no significant difference in the expression of p53 between normal and tumor cells (p>0.05). When the immunohistochemical results of glutathione-S-transferase isoenzymes and p53 were correlated with the clinical parameters, there were no significant associations between glutathione-S-transferases and p53 expressions and tumor stage, tumor grade and smoking status (p>0.05).