Abstract Background Palliative radiotherapy (RT) represents an important treatment opportunity for improving the quality of life in metastatic non-small cell lung cancer (NSCLC) patients through the management of symptoms within the course of the illness. The aim of the study is to determine the proportion of patients who had palliative RT within 12 months of diagnosis and evaluate the factors associated with it. Methods A retrospective cohort study was performed using secondary data analysis from 2009 to 2015 from the Puerto Rico Central Cancer Registry–Health Insurance Linkage Database (PRCCR-HILD). A logistic regression model was used to examine factors associated with palliative RT. Results Among the 929 patients identified with metastatic NSCLC, 33.80% received palliative RT within the first year after diagnosis. After adjusting for other covariates, receipt of chemotherapy (ORAdj = 3.90; 95% CI = 2.91–5.45; P