Background: The availability of valid and reliable instruments, based on current competency frameworks, is essential to respond to the need for accurate measurement of the competency of registered nurses in evidence-based practice (EBP). Aims: To develop and validate a questionnaire capable of measuring EBP competencies in registered nurses following the competency framework developed by Melynk et al. (2014). Methods: The study was developed in two stages: (a) creation of the questionnaire based on an operational definition of the construct, its face, and content validation by 10 experts, and cognitive piloting; (b) psychometric evaluation of the questionnaire by a cross-sectional, and multicenter study between February and November 2018. Analyses were conducted of the questionnaire's reliability and construct validity (exploratory [EFA] and confirmatory [CFA] factor analyses). Results: First phase: The initial version of EBP-COQ© Prof contained 50 items grouped into four dimensions (attitudes, knowledge, skills, and utilization). After two expert validation rounds, a 35-item version was obtained with content validity index of 0.86. Second phase: The questionnaire was completed by 579 nurses; EFA with PROMAX rotation revealed that the fourfactor model had the best fit (χ 2 = 311.32; p = .001, root mean square error of approximation [RMSEA] = 0.000, 90% confidence interval [CI] = 0.000-0.010; comparative fit index [CFI] = 1), and it showed a good CFA fit index: CFI = 0.932, and RMSEA = 0.093 (90% CI = 0.097 − 0.108). Cronbach's α for each factor ranged from 0.817 (factor III) to 0.948 (factor II). Linking Evidence to Action: EBP-COQ Prof© is a valid, reliable, and easily administered questionnaire that measures the self-perceived competency of registered nurses in EBP based on an updated and specific competency framework. It permits the independent evaluation of attitudes, knowledge, and skills related to EBP and of its utilization in hospital and primary care settings, allowing the monitoring of compliance with EBP.