Introduction: Prognostic value of easily available and reproducible laboratory parameters is investigated for non-small cell lung cancer (NSCLC) of which mortality is still high. We aimed to determine the prognostic value of blood urea nitrogen/albumin (BUN/ albumin) ratio. Methods: Clinicopathological characteristics with treatment modalities and laboratory values of NSCLC patients at our center evaluated retrospectively. A total of 142 patients were included to the study. Results: Median age was 57 (range 26-83). Receiver operating characteristic (ROC) curves for overall survival prediction were plotted to verify the optimum cut-off point for BUN/albumin ratio. The recommended cut-off values for BUN/albumin ratio was 0.80 with a sensitivity of 60.0% and a specificity of 60.0%. While median overall survival was 26.0 (95% CI: 14.2-37.7) months in the group with low BUN/albumin ratio (<0.80), it was calculated as 10.0 (95% CI: 5.2-14.8) months in the group with high BUN/albumin ratio (≥0.80). The difference between groups was statistically significant (p=0.005). Conclusion: BUN/albumin ratio seems to be a significant prognostic index in NSCLC. It is not only simple but also inexpensive and reproducible. However, it needs further prospective trials with large number of patients.