The phenomenon of bilingualism in science has become naturalized in our society. Even so, there is still a lot of work to be done for this process to be successful in school. The starting point of this chapter is the analysis and understanding of the identities of bilingual science teachers across various dimensions: their training, their actions, their struggles, and the way they conceive the process. The documentary review allowed us to identify some related works on said aspects, but the results show that, in our context, this path is still unexplored; therefore, we must work on its deconstruction in order to generate new knowledge that enriches the fields of English language learning and teaching (ELT) and science didactics, since it is not possible to speak of bilingualism and identities without taking into account the knowledge produced in these two fields.