Background: Inflammation is a critical component of tumor progression. Many cancers arise from sites of infection, chronic irritation, and inflammation. It is now becoming clear that the tumour microenvironment, which is largely orchestrated by inflammatory cells, is an essential participant in the neoplastic process, promoting proliferation, survival and migration. Platelets can release some growth factors such as platelet-derived growth factor, platelet factor 4, and thrombospondin. Such factors have been shown to promote hematogenous tumour spread, tumor cell adhesion and invasion, and angiogenesis and to play an important role in tumor progression. In this study, we aimed to investigate effects of the pretreatment neutrophil to lymphocyte ratio (NLR) and the platelet to lymphocyte ratio (PLR) on survival and response to chemoradiotherapy in patients with non-small-cell lung cancer (NSCLC). Materials and Methods: Ninety-four patients with non-metastatic NSCLC were included and separated into two groups according to median valuse of NLR and PLR (low:<3.44 or high:${geq}3.44$ and low:<194 or high${geq}194$, respectively). Results: Pretreatment high NLR and PLR were associated with significantly shorter disease-free and overall survival rates. Multivariate analysis revealed that the overall survival rates were significantly linked with PLR (OR: 1.87, CI: 1.20-2.91, p: 0.006) and response to chemoradiotherapy (OR: 1.80, CI: 1.14-2.81, p: 0.012) and the disease-free survival rates were significantly associated with NLR (OR: 1.81, CI: 1.16-2.82, p: 0.009) and response to chemoradiotherapy (OR: 2.30, CI: 1.45-3.66, p: 0.001). There was no significant difference between patients with high and low NLR in terms of response to chemoradiotherapy. Similarly, there was no significant influence of the PLR. Conclusions: Pretreatment NLR and PLR measurements can provide important prognostic results in patients with NSCLC and assessment of the two parameters together appears to better predict the prognosis in patients with NSCLC. The effect of inflammation, indicators of NLR and PLR, on survival seems independent of the response to chemoradiotherapy.