Online learning is a reality in much of the world. Among the tools available for online learning, there are Online Discussion Forums (ODF), due to their potential to promote collaborative learning. However, there is a lack in the literature about the evaluation of the forums, a gap marked by the absence of quantitative tools that make it possible to evaluate the forums from the student's perspective. In this sense, the objective of this paper was to develop and validate a Quality Perception of Online Discussion Forums (QPODF) scale. To this end, quantitative research was carried out with students of postgraduate courses "lato sensu" the online distance education. Exploratory factor analysis and confirmatory factor analysis was used to validate the QPODF scale. The results demonstrate that the quality of the construct perceived online discussion forums has two dimensions "Forum Structure" and "Forum Mediation." The two identified factors were shown to be consistent and accurate to measure the quality of online forums. Moreover, the theoretical approach used to compose the scale is convergent with the measurement model proposed in the paper.