OBJECTIVES: In order to estimate the benefits of health interventions, health related quality of life (HR-QoL) measures are traditionally mapped into utilities based on a valuation by a representative sample of the general population. However, in order to apply such valuations in cost-effectiveness studies of programs addressed to patients, it needs to be ascertained that the values of these patients are not different than these of the population. Therefore we compared the valuation of chronic patients with the already published valuation of the general population. METHODS: Between December 2009 and March 2010 the EQ-5D questionnaire was distributed in 15 outpatient services, treating adult (age > 18 yrs) chronically ill patients in the University Hospital Ghent, Belgium. In Belgium the EQ-5D was mapped previously to the Visual Analogue Score (VAS), hence patients in our study were also asked to indicate their actual perception of HR-QoL on a VAS scale. Only EQ-5D profiles which were scored at least 10 times by different patients were considered for further evaluation. All profiles were mapped into VAS by multivariate regression. RESULTS:   A total of 1348 questionnaires were distributed, of which 768 (57%) were completed. Male/female ratio was 41%/59%, with a mean age of 53.6. Eighteen EQ-5D profiles were scored at least 10 times, with a mean VAS of 0.64 (95% C.I. 0.63-0.66). The complete set of utilities obtained by multivariate regression was significantly different compared to the valuation by the Belgian population sample (p<0.0001). Especially in the profiles in which the patient indicates complete dependency or major problems, the HR-QoL value was perceived much higher by patients as compared to the general population. CONCLUSIONS: Chronically ill patients perceive their HR-QoL higher than estimated by the population sample. In order to evaluate health programs consequences of these findings should be considered.