Objective: EGFR, ERCC1, RRM1 and βTubulinIII predicts sensitivity to therapeutic agents and provide prognostic information in Nonsmall cell lung cancer (NSCLC) which is the most frequent worldwide cause of cancer death. Method: We investigated the expressions of EGFR, ERCC1, βTubulinIII, RRM1 immunohistochemically in 42 advanced NSCLC cases and their correlations with other pathologic features. Results: The age distribution was 30-82 with an average of 63,02. Male/female ratio was 34/8. ERCC1 protein was detected in nuclei of carcinoma cells in 38 patients (90,5 %) (H score >1). ΒTubulinIII expression was detected in cytoplasm of cancer cells in 41 patients (97,6 %) (score ≥ 50). ERCC1 and βTubulinIII expression were not associated with pathological factors. RRM1 was negative (score<9) in 29 (69 %) cases and negativity was significantly correlated with male gender (p<0,032). EGFR was negative (score<200) in 40 (95,2 %) cases and negativity was nearly correlated with absent necrosis (p<0,065). No significant correlations were found between EGFR, ERCC1, βTubuli-nIII, RRM1 and the pathological parameters. Conclusion: In our study, as a first step, EGFR, ERCC1, βTubulinIII, RRM1 showed no significant correlation with pathologic features. We look forward to obtain further results in the next study consisting of correlations with follow ups.