The term participation is widely known and used and has a vast network of meanings in different contexts. In addition, the discussion on participation in museums is related to the issue of social inclusion and engagement. The objective of this research is to understand the current role of Brazilian science museums with regard to social participation in science and technology. Thus, the educational actions developed in these spaces that have explicit objectives of promoting social participation and the meanings attributed to the concept of social participation by museal educators were investigated in the light of the historical-cultural approach that has its origin in Vigostski's thoughts. This approach allows for a deeper understanding of the processes of construction of personal and social meanings in their entirety, including their contradictions and negotiation of meanings and the concept-building process. In the first stage of the research, a survey was carried out with the objective of identifying the participatory actions developed in museums registered with the Brazilian Association of Science Centers and Museums (ABCMC) through a questionnaire. Along with the survey described, a bibliographic review was carried out. The following texts were taken from the texts resulting from the review: the descriptions of actions considered by the participative or inclusive authors and the conceptions presented by the authors regarding the terms studied. The analysis units from the bibliographic research were placed in dialogue with the perceptions presented in the answers given by the professionals to the initial questionnaire. Based on the effort to negotiate and articulate educators' perceptions about the practices developed in their institutions and the theoretical concepts studied, we recognize some elements that we consider as forming the concept of social participation in science museums: "access", "identity and diversity","co-creation and authorship"," interaction and dialogue" and "exercise of citizenship". Based on the proposed elements, a second questionnaire was prepared and aimed at museum educators. Their responses reinforced and / or changed the descriptions of these elements. As a result, we recognize limitations, but also different entry points for social participation in these institutions and we understand that the elements that form the concept of social participation can contribute to the discussion and elaboration of meanings and museal practices that dialogue with communities, that strengthen the participation and engagement of different audiences in science and which have the potential to transform social reality and the museums themselves.