OBJECTIVES: To contribute to the debate of using patients vs. general population preferences for valuing health states by obtaining patients based valuation of hypothetical health state and determine whether the preferences towards HRQoLdiffer between both groups. METHODS: Values of hypothetical health states were acquired in face-to-face interviews of 611 metastatic breast cancer and rheumatoid arthritis patients in Spain, using EQ-5D-5L instrument. 20 health states were included in the EQ-VT design, which was developed specifically for use in ADVANCE HTA study. The ethical approval was obtained and training program was conducted for the interviewers. The interviews were carried out by GEPAC, the Spanish Group for Cancer Patients between June and November 2015. Patients were selected according to their willingness to participate and were selected from patient organizations and hospitals in Madrid. The data quality was performed. Data analysis was performed using R. The differences between each pair of health states were checked and causes of differences were determined using linear regression models. RESULTS: Patients, regardless of the disease, have similar preferences towards hypothetical health states, yet different to the general population. The average absolute difference between general and patient population is 0.232, while the average absolute difference between RA and BC patient group is 0.073. We found statistically significant differences between patients’ valuations and general public valuations on three health dimensions: mobility, pain or discomfort, and anxiety or depression. Patients consider problems related to mobility less problematic, while problems related to pain/anxiety are seen as more problematic CONCLUSIONS: The results suggest that not all health dimensions defined by EQ-5D are equally well understood by the general public. A possible explanation for the differences in the valuation that is suggested by the regression analysis is that problems with mobility, self-care, and usual activities are easier to imagine and understand by general population.