OBJECTIVES: ZOL is efficacious vs. PBO in reducing the risk of skeletal-related events (SREs) in lung cancer (LC) patients with bone metastases. Limited information exists on its economic impact. This study assessed the cost-effectiveness of ZOL in the LC setting in France (FR), Germany (DE), United Kingdom (UK), Portugal (PT), and the Netherlands (NL). METHODS: Comparisons of direct costs and quality-adjusted life years (QALY) between patients on ZOL vs. PBO were assessed using a literature-based model. Clinical information on survival, SRE incidence and infusions administered were obtained from a randomised clinical trial in LC patients, comparing 4 mg ZOL (every 3 weeks for 21 months) to PBO. Drug acquisition and administration costs were obtained from publicly available sources. SRE costs were obtained from Diagnosis-Related Group (DRG) tariffs and published information in FR, UK, and DE and from retrospective medical record reviews in NL and PT. RESULTS: The expected average survival for patients on ZOL and placebo was the same (8.5 months [median=5.89 months]). Per-patient (pp) SRE occurrence was projected to be higher and QALYs lower in PBO group (SREs=2.07; QALYs=0.292) vs. ZOL-treated patients (SREs=1.32; QALYs=0.352). ZOL drug-related costs ranged from €1510 in DE and €1484 per patient (pp) in UK. The use of ZOL was associated with a reduction in SRE costs ranging from €1.15 pp in FR to €1942 pp in NL. Overall, ZOL saved €319 pp in NL, followed by €291 in DE, €216 in UK, €67 in PT, and €2 in FR. In sensitivity analysis the cost per QALY gained remained under €50,000 in a wide range of scenarios.CONCLUSIONS: ZOL leads to fewer SREs and better estimated quality of life. This multinational evaluation reports ZOL to be a highly cost-effective treatment relative to PBO for LC patients with bone metastases.