This record contains raw data related to article “Neutrophil and lymphocyte blood count as potential predictive indicators of nivolumab efficacy in metastatic non-small-cell lung cancer" The use of immune checkpoint inhibitors in pretreated metastatic non-small-cell lung cancer (mNSCLC) is, to date, limited by the lack of biomarkers able to reliably select patients that could potentially benefit from treatment and exclude subjects with intrinsic resistance. The aim of the present study is to evaluate the role of neutrophil-to-lymphocyte ratio (NLR) and lymphocyte-to-monocyte ratio (LMR) as prognostic factors in mNSCLC patients treated with nivolumab. In this stud, medical records of 65 patients affected by mNSCLC and treated with nivolumab were retrospectively reviewed. NLR and LMR were calculated at baseline (t0) and at first radiological tumor assessment (t1).