OBJECTIVES: The purposes of this study are to validate the indicator of Oral Health Impact Profile for edentulous patients (OHIP-20sp) in the Spanish population and to analyze the factorial construct of the prosthetic well-being. STUDY DESIGN: [corrected] A total of twenty-one (n=21) edentulous patients wearing mandibular implant-overdentures on Locator® (LO) and twenty (n=20) with complete dentures (CD) were retrospectively evaluated in this study. All participants were recruited consecutively and were treated in the previous academic year 2009-2010 by professors of the University of Salamanca. Reliability analyses and validity tests were performed in order to evaluate the psychometric properties of OHIP-20sp employing two different total score methods (additional and simple count). A retrospective evaluation of the impact of the prosthetic treatment was captured with an evaluative instrument derived from OHIP-20, and named POST-OHIP-13. RESULTS: The reliability coefficient (Cronbach's alpha = 0.91) has shown a high internal consistency. Item-total correlations coefficients ranged from 0.46 and 0.81. Five factors, named as disability, functional comfort, psychosocial impact, pain-discomfort and functional limitations were identified as principal components of the construct, explaining almost 85% of the variance. The 48% of the sample felt at least one impact in an occasional or more frequently manner (generally food packing). The global transition judgment of the prosthetic treatment using the POST-OHIP-13 was significantly higher in group LO than in the CD group. CONCLUSIONS: OHIP-20 seems to be a reliable and valid indicator to measure oral impact and satisfaction in the Spanish edentulous population. The underlying construct is comprised by 5 factors named as disability, functional comfort, psychosocial impact, pain-discomfort and functional limitations.