For more information regarding Bristol-Myers Squibb Clinical Trial participation, please visit www.BMSStudyConnect.com  Inclusion Criteria:  Male or female adult Greek-speaking patients, of any race (residing in Greece or Cyprus), aged at least 18 years at time of initiation of nivolumab treatment. Histologically- or cytologically-confirmed diagnosis of locally advanced or metastatic (stage IIIB-IV) Non-Small Cell Lung Cancer (NSCLC) with Squamous Cell Carcinoma (SCC) or Non-Squamous Cell Carcinoma (NSCC) histological subtype Initiated on second or third line treatment with nivolumab as monotherapy after prior chemotherapy as per the product's Summary of Product Characteristics (SmPC) prior to informed consent obtainment, and for whom therapy is ongoing and no more than one infusion has been administered from treatment initiation to obtaining the signed informed consent Decision to prescribe nivolumab treatment has been taken prior to their enrollment in the study and is clearly separated from the physician's decision to include the patient in the current study Provided signed informed consent for participating in the study and for collecting and analyzing medical data pertinent to the objectives of this study  Exclusion Criteria:  Current primary diagnosis of a cancer other than NSCLC that requires systemic or other treatment Previously treated with nivolumab or other non-chemotherapy agents, with the exception of immune checkpoint inhibitors (anti-PD-1(Programmed cell death-1)/anti-PD-L1 (Programmed death-ligand 1) agent, other than nivolumab) administered in combination with chemotherapy Currently receiving or are planned to receive treatment with any investigational drug/device/intervention or who have received any investigational product within 1 month or 5 half-lives of the investigational agent (whichever is longer) prior to nivolumab therapy initiation