Inclusion Criteria: 1. Adult patients (at least 18 years of age at time of treatment decision) - Diagnosis of SCCHN and patients are progressing on or after platinum-based therapy - Diagnosis of SCCHN has been confirmed by histology or cytology (either at initial diagnosis or any time later during the course of the disease) - Treatment decision to initiate a treatment with nivolumab for the first time for the treatment of SCCHN (according to the label approved in Germany) has already been taken 2. Patients who provided informed consent to participate in the study Exclusion Criteria: 1. Patients with a current primary diagnosis of a cancer other than SCCHN, ie, a cancer other than SCCHN that requires systemic or other treatment, or has not been treated curatively (as per discretion of the investigator) 2. Patients previously treated with nivolumab and/or ipilimumab, an anti-PD-1, anti-PD-L1, anti-PD-L2, anti-CTLA-4 antibody, or any other antibody or drug specifically targeting T-cell co-stimulation or immune checkpoint pathways (applicable for any indication) 3. Patients currently included in an interventional clinical trial for their SCCHN. Patients who have completed their participation in an interventional trial; or who are not receiving study drug anymore and who are only followed-up for OS can be enrolled