OBJECTIVES: To carry-out the cultural adaptation into Spanish (for Spain) of the questionnaire "Overactive Bladder - Family Impact Measure (OAB-FIM)". METHODS: The adaptation included linguistic validation through forward and back translations in duplicate, reviewed by a panel experts and a debriefing with relatives of OAB patients, and a phase of preliminary measurement of psychometric properties in OAB patients and their relatives of habitual coexistence, of both genders, ≥18 years of age, newly diagnosed and on-therapy for their symptoms of OAB. Conceptual and linguistic equivalences, internal consistency (α-Cronbach), content validity (the inter-rater Rovinelli-Hambleton index of item congruence) and construct validity were measured. Construct validity included concurrent validity (with scales ZARIT and OABq-SF), and validity of known groups according to the benefit of treatment with TBS scale. Feasibility and burden of administration were also measured. RESULTS: