ObjectivesTo develop and validate an instrument to measure Brazilian healthcare professionals’ perceptions, behaviour, self-efficacy and attitudes towards evidence-based health practice.DesignValidation of an instrument using the Delphi method to ensure content validity and data from a cross-sectional survey to evaluate psychometric characteristics (psychometric sensitivity, factorial validity and reliability).SettingNational Register of Health Establishments database.ParticipantsWe included clinical health professionals who were working in the Brazilian public health system.ResultsThe Instrument to assess Evidence-Based Health (I-SABE) was constructed with five domains: self-efficacy; behaviour; attitude; results/benefits and knowledge/skills. Content validity was done by 10–12 experts (three rounds). We applied I-SABE to 217 health professionals. Bartlett’s sphericity test and the Kaiser-Meyer-Olkin (KMO) index were adequate (χ²=1455.810, p<0.001; KMO=0.847). Considering the factorial loads of the items and the convergence between the Scree Plot and the Kaiser criterion the four domains tested in this analysis, explaining 59.2% of the total variance. The internal consistency varied between the domains: self-efficacy (α=0.76), behaviour (α=0.30), attitudes (α=0.644), results/benefits to the patient (α=0.835).ConclusionsThe results of the psychometric analysis of the I-SABE confirm the good quality of this tool. The I-SABE can be used both in educational activities as well as an assessment tool among healthcare professionals in the Brazilian public health settings.