Background: Metastatic non-small-cell lung (NSCLC) cancer has a poor prognosis, with a 5 year survival less than 5%. The majority of patients present with stage IV and many patients treated curatively with stage I-III will develop recurrent metastatic disease. It is unknown if the natural history differs between patients with recurrent versus de novo metastatic NSCLC. We hypothesized that de novo metastatic disease is associated with decreased overall survival compared to recurrent metastatic disease. Methods: A retrospective review was completed of all patients with NSCLC referred to the BC Cancer Agency from 2005-2012. Two cohorts were created; de novo metastatic disease and patients treated with curative intent (surgery or radiotherapy) that developed recurrent, metastatic disease. Information was collected on known prognostic and predictive factors. Overall survival was calculated from the date of diagnosis of metastatic disease. Results: A total of 9656 patients were referred, 5783 (60%) with de novo stage IV disease, and 3873 (40%) with stage I-III disease. Of patients with initial stage I-III, 1801 received curative therapy (751 surgery, 1050 radiotherapy) and 802 developed metastases. Patients in the de novo cohort were more likely to be male (52% vs 47%), have poorer performance status (ECOG≥2 50% vs 43%), and receive no palliative chemotherapy (67% vs 61%). The median overall survival in the de novo cohort was 4.7 m vs 6.9 m in the recurrent cohort (p < 0.001). De novo status was associated with shorter overall survival and this remained significant in a multivariate model that incorporated gender, ECOG and lines of palliative chemotherapy (hazard ratio 1.228[95% confidence interval 1.134-1.330], p-value < 0.001). Conclusions: In a large population based study of NSCLC, de novo metastatic status was independently associated with decreased overall survival from the time of metastatic disease diagnosis. De novo versus recurrent status should be used as a prognostic factor to inform patient decisions and ensure balanced stratification of patients in clinical trials.