INTRODUCTION: Approximately 80-85% of lung cancer patients are diagnosed with non-small-cell lung cancer (NSCLC), of which 50% of patients present with advanced or metastatic disease. The objective of this study was to describe treatment patterns, use of resources and costs associated with treating advanced or metastatic NSCLC patients in Spain. METHODS: A two-round Delphi consensus panel of clinical experts was carried out to describe local clinical patterns based on treatment algorithms from SEOM and ASCO treatment guidelines. The panel consisted of 19 oncologists and 1 hospital pharmacist, who were asked during the first round to define therapeutic pathways for NSCLC by the patients' performance status, age and histology; to quantify the use of resources associated with the preparation and administration of anticancer pharmacotherapy; management of adverse events associated with anticancer pharmacotherapy; and best supportive care (BSC). The second round was used to try to reduce the variability of responses in some questions and to further describe differences between intravenous and oral therapy. 2009 unit costs were applied to the use of resources described by the clinical experts. The perspective of the study was from the Spanish National Healthcare System. RESULTS: Performance status guided therapy decision and led to differences in costs. Patients with a performance status of 0-2 were expected to receive anticancer pharmacotherapy while patients with a performance status of 3-4 received BSC including analgesics and corticosteroids. Anticancer pharmacotherapies containing cisplatin or carboplatin were used preferably in first-line treatment, while the usual second- and third-line treatments were docetaxel, erlotinib or pemetrexed monotherapy. The importance of the cost of anticancer pharmacotherapy as a proportion of total healthcare costs was higher for combination therapies containing bevacizumab or pemetrexed. The anticancer pharmacotherapies associated with adverse events like febrile neutropenia or infection increased the total treatment cost. Administration costs were more relevant in regimens containing cisplatin and were low for orally administered therapies. The total cost per patient with advanced or metastatic NSCLC from starting anticancer therapy until death was estimated to be between €11,301 and €32,754 depending on the number of treatment lines received. CONCLUSIONS: In the treatment of advanced or metastatic NSCLC, healthcare costs are impacted by line of treatment, patient performance status, type of administration of therapy and adverse event management.