Importance of a lot of prognostic factors has been pointed out in recent years. Prognostic significance of blood group antigens, one of the biological mar-kers, have also attained clinical relevance. Blood group antigen expression of paraffin embedded tumor tissues of 92 lung cancer patients and relation of this with survival was investigated in this study. Immunohistochemical staining were performed. Of 77 non-small cell lung cancer patients who had blood group A had longer median survival than other blood groups (p=0,04). Presence of blood group antigen A expression in tumor tissue seemed to result in longer median survival than loss of antigenic expression in patients with blood group A (p=0,009). Statistical analysis was not performed in 15 small cell lung cancer patients because of insufficient data. We had documented that blood group antigen A expression of tumor tissue in nonsmall cell lung cancer has a favorable prognostic value in this, as far as we know, first study in Turkey.