As we face a period characterized by a paradigmatic transition between Modernity and Post-Modernity, how would the science conceptions of science/biology teachers fit in this scenery? What would be their positions regarding the curricular reformation set in the 90`s after the publication of the PCN of Natural Sciences and transversal themes? How the main multicultural themes race, gender and sexual orientation are presented inside their speech? This work presents a research which has seek to comprehend how the science and biology teachers from an elite school at Rio de Janeiro represent scientific knowledge, science curriculum and their possible implications concerning the main multicultural issues (race, gender and sexual orientation). Therefore, it has been chosen a qualitative research using two instruments: (1) documental analyses of the Natural Sciences PCN and transversal themes and (2) semi-structural interviews. It was evident a tendency among the teachers discourses to oscillate between a more traditional and modern science view and a more post-modern approach. This kind of posture that was also identified regarding the multicultural issues would be in agreement with both the curricular proposals inside the PCNs and as a reflection of the transitional period in which we are immersed. This work aims to contribute with the debate regarding possible progress and limits of a multicultural (post-modern) epistemology inside science teaching.