Background: To clarify the clinical significance of the aortic nodes in resected non-small cell lung cancer of the left upper lobe. Material and Method: One hundred fifty six patients with resected non-small cell lung cancer of the left upper lobe were studied. Patients who received preoperative induction therapy, non-curative operation or defined as operative mortality were excluded from this study. Result: In N2 left upper lobe tumors, aortic nodes comprised 52.7% of the metastatic mediastinal lymph nodes. In single station N2 disease, a frequently metastasized station was aortic node (64.3%). 5-year actuarial survival according to the N status was 65.0% in N0, 30.4% in N1, and 17.9% in N2. There was no statistically significant difference in survival between N1 and N2 diseases (p=0.06). The patients with metastasis to aortic node alone had a comparatively good prognosis (5-year survival: 35.6%) than other N2 diseases (5-year survival: 4.6%) (p=0.01) and had a similar survival outcome as N1 diseases (p=0.97). Considering the aortic node as N1 node, 5-year survival according to the N status was 65.0% in N0, 31.2% in N1, 4.6% in N2 and significant survival difference was observed between N1 and N2 disease (p=0.00). In multivariate analysis, the male sex (hazard ratio 6.892, p=0.011) and the involvement to the aortic node alone (hazards ratio 2.799, p=0.009) were the significant factors affecting postoperative survival. Conclusion: According to the our data, involvement to the aortic node alone in left upper lobe tumors should be grouped with N1 disease because this combined category reflects the surgical outcome more accurately.