It has been postulated that transfusions have immunosuppressive effects that promote tumor growth and metastasis. Moreover perioperative anemia is considered an independent prognostic factor on outcome in patients operated for malignancy. We evaluated the influence of red blood cell (RBC) transfusions and perioperative anemia on survival in non-small cell lung carcinoma (NSCLC) patients. From 1999 through 2005, 331 consecutive patients, male/female=295/36 (mean age 64+/-9 years), who underwent radical surgery for NSCLC were prospectively enrolled in this cohort and followed up for a mean of 27.2 months. The overall survival of patients was analyzed in relation to RBC transfusions and perioperative anemia. These parameters were analyzed in the whole cohort of patients and separately for stage I patients. Patients were divided according to perioperative transfusion, into Group A (transfused) and Group B (non-transfused) and according to the preoperative haemoglobin (Hb) level into Group 1(Hb<12g/dl) and Group 2(Hb> or =12g/dl), respectively. The overall transfusion rate was 25.7%. Univariate analysis showed that in the whole cohort of patients overall survival was significantly shorter in Group A (mean 33.6 months, 5-year survival 25.1%) compared to Group B (mean 48.0 months, 5-year survival 37.3%) (p=0.001). It also showed that patients with preoperative Hb level <12g/dl (Group 1), (mean of 33.0 months, 5-year survival 21.3%) had shorter survival compared to Group 2 patients (mean 49.3 months and 5-year survival 40.0%), respectively (p=0.002). Multivariate analysis in the whole cohort of patients showed that preoperative anemia was an independent risk factor for survival while RBC transfusion was not. In particular for stage I patients, it was shown that RBC transfusion was an independent prognostic factor for long-term survival as detected by multivariate analysis (p=0.043), while anemia was not. RBC transfusions affect adversely the survival of stage I NSCLC patients, while do not exert any effect on survival of patients with surgically resectable more advanced disease, where preoperative anemia is an independent negative prognostic factor. These findings indicate that RBC transfusion might exert an immunomodulatory effect on patients with early disease while in more advanced stages this effect is not apparent.