OBJECTIVES: To develop a mapping algorithm to transform the Overactive Bladder questionnaire-Short Form (OABq-SF) questionnaire responses into EQ-5D derived utilities in patients with OAB in Spain. METHODS: The culturally adapted Spanish versions of OABq-SF and EQ-5D questionnaires were self-administered on two occasions 3 months apart to a set of patients of  both genders, above 18 years, diagnosed of OAB according with standard criteria and a score > 8 in the OAB-V8 scale and able to understand PRO instruments written in Spanish. Patients were recruited consecutively in clinics of Urology all over the country. Linear correlations between symptoms severity and health-related quality-of-life (HRQoL) domains of the OABq-SF and EQ-5D (VAS and TTO-tariffs) were computed. A combined score of both domains of OABq-SF was used to obtain a unique scoring per patient, although mapping was developed for both combined and separated punctuations of the OABq-SF using regression modelling. RESULTS: A total of 199 OAB patients (58.4 years, 74% women, 99% Caucasian, 37% workers and 36% primary schooling) from 18 urological clinics were evaluated. Utility values ranged from 1 to 0.01; mean value= 0.7623 (SD= 0.2292) and median = 0.79. Correlations with EQ-5D were -0.282 and -0.301 for the severity of symptoms domain at baseline an after 3 months of a medical intervention, and 0.329 and 0.369 for the HRQoL domain, respectively. Pearson coefficients for combined scoring were -0.331 and -0.351, respectively.  All coefficients were significant at p<0.001 level. Observed relation between utilities and combined score followed a linear although heterocedastic pattern. Utilities distribution was clearly positively skewed with benign utilities prevailing. CONCLUSIONS: Utilities values for Spanish patients with OAB were mostly mild to moderate in the 0-1 range. A utility map was obtained for different levels of scoring in the OABq-SF questionnaire, which is useful to derive Quality-adjusted Life-year gain in economic evaluations