For several decades, scientific papers amass studies about teachers and future teachers’ grade retention conceptions. This had for consequence the creation of numerous questionnaires, which differ regarding the investigated subscales. But, surprisingly, few papers relate to these various instruments and no study, as far as we are concerned, examines thoroughly their psychometric validity. Anyway, none of these questionnaires is considered today as the reference regarding the research on teachers and future teachers’ grade retention conceptions. The present study, financed by Swiss National Fund of research (Crahay & Marcoux, 2010), within the framework of trying to analyze the structure and the evolution of grade retention conceptions, aims at building and validating a scale specifically based on existing questionnaires. Data collection took place at Geneva University with students registered in elementary education program. in conclusion, two scales have been obtained: one about « grade retention conceptions» and another about «knowledge about grade retention researches». Statistical results reveal that these scales present good indications of reliability (Cronbach alpha) as well as a good internal structure, established from exploratory and confirmatory factor analyses.