The purpose of this thesis was to study and define the concept of symbolic function, specifically from the Genetic Epistemology of Jean Piaget and the Cultural-Historical Psychology of Lev S. Vigotsky. The different contributions of each of these currents on this complex psychological process were investigated and compared in order to offer a synthesis of the concept. In addition, a search was made on the different existing measurement instruments to evaluate it and they were systematically presented. The design was theoretical of bibliographic review, so that the material investigated was analyzed in a critical and integrative manner.