OBJECTIVES: The primary objective of this study was to identify the total intramural cost of illness of metastatic non-small cell lung cancer (NSCLC) in the Netherlands between 2006-2012. Secondary objective was to identify whether changes in cost patterns of metastatic NSCLC have occurred over the last years. METHODS: Patients diagnosed with metastatic NSCLC between 1-1-2006 and 31-12-2012, who had follow-up to death or the date of data cut-off and no trial participation were included. A structured chart review was performed using a case report form. Data collection started after diagnosis of metastatic NSCLC and ended at death or April first, 2015. Data regarding outpatient visits, clinical attendance, oncolytic drug use, imaging, lab tests, radiotherapy and surgery were collected. RESULTS: Sixty-seven patients were included with a median age of 67 years. The median follow-up was 234days. On average patients had 28 outpatient visits and 11 inpatient days. Oncolytic drugs were administered to 76% of the patients. Mean per patient expenditures amounted up to €17,463, with oncolytic drugs (€6,390) as the main cost driver. In comparison with the time-period of 2003-2005 total per patient per year expenses decreased by 44%. The contribution to total yearly costs of oncolytic drugs increased from 18% to 35%, while costs for inpatient stay decreased from 52% to 28% of total expenditures. CONCLUSION: Outcomes in this study demonstrate that average treatment costs for metastatic NSCLC in the Netherlands Cancer Institute amount to €17,463. Compared to a prior study the average cost for metastatic NSCLC over time in the Netherlands has decreased. A shift of main cost drivers seems to have occurred from inpatient stay, to oncolytic drugs as main contributor. The shift towards treatment cost might become more visible with the introduction of immunotherapy. These results mark the importance of up-to-date cost of illness studies.