OBJECTIVES: Despite metastatic breast cancer (MBC) being a leading cause of morbidity and mortality, there is little real-world evidence (RWE) regarding the impact on preference-based measures of health-related quality of life (HRQoL). The objective of this analysis was to report health state utility scores collected from European MBC patients and compare these with previously published utility values estimates based on using mapping and vignette methodologies. METHODS: A retrospective patient record form study and a cross-sectional patient survey (conducted Jan-Jun 2015) collected data from 788 patients across France, Germany, Italy, Spain and United Kingdom. Each patient provided consent for de-identified and aggregated reporting of research findings. Data on patients’ current health state – either stable disease (SD), tumor response (TR), or disease progression (DP)-  treatment toxicities and HRQoL (EQ-5D) were collected. EQ-5D was scored using the UK tariff. Independent linear mixed-effects models adjusting for baseline health state were used to report disutilities for common adverse events.  RESULTS: Mean MBC patients’ EQ-5D scores were for SD  0.671 (standard deviation (sd) 0.324), for TR  0.755 (sd 0.24), and for DP 0.614 (sd 0.374).  In comparison to the two alternative studies, there was a smaller absolute difference vs. mapped utilities and differences vs.  vignette utilities (mapped vs. vignette: SD: 0.697 vs.  0.715, TR: 0.782 vs. 0.790, DP 0.679 vs. 0.443). Disutilities were calculated for nausea, vomiting, fatigue, pain, hair loss and other common adverse events. CONCLUSIONS: This analysis reports HRQoL data in the form of utilities from MBC patients in a real world setting.  MBC has a substantial impact on patients’ HRQoL, especially after disease progression. The comparison of utilities from different sources indicates substantial variability and suggests that standardising methods will reduce uncertainty.  We would suggest that EQ-5D data from real world studies, free from bias, should be the preferred approach.