Incurable head and neck cancer has a poor prognosis and impairs a patient’s health-related quality of life. Palliative radiotherapy may improve or stabilize health-related quality of life and symptoms, best measured by patient-reported outcomes. There is no systematic analysis if palliative radiotherapy for head and neck cancer improves or stabilizes health-related quality of life or symptoms as validly measured by patient-reported outcomes. Therefore, the primary objective of this systematic review (PROSPERO-ID: CRD42020166434) was to assess the effect of palliative radiotherapy for head and neck cancer on patient-reported outcomes. The secondary objective was to assess the rate and quality of use of patient-reported outcomes in relevant studies claiming a “palliative effect” of radiotherapy. The databases MEDLINE/PubMed, EMBASE, Cochrane CENTRAL, “ClinicalTrials.gov” were searched. Concerning the primary objective, four studies were eligible to assess the effectiveness of palliative radiotherapy as measured by patient-reported outcomes. A narrative synthesis suggests a favorable impact of palliative radiotherapy on health-related quality of life and symptom burden. The risk of bias, however, is considerable and the overall quality of evidence low. Concerning the secondary objective, over 90% of studies claiming a “palliative effect” of palliative radiotherapy did either not use patient-reported outcomes or did so by limited quality. In conclusion, implementation of patient-reported outcomes in studies assessing palliative radiotherapy for head and neck cancer should be fostered. Palliative radiotherapy remains an option for head and neck cancer patients, although more studies focusing on patient-reported outcomes are needed.Systematic Review Registrationhttps://www.crd.york.ac.uk/prospero/, identifier CRD42020166434