This article aims to discuss the purpose of ethnobiology in biology teachers' training based on conceptions of biology teachers before and after their participation in a training course for science teachers that involved ethnobiology. The research was developed in 2009 and involved semi-structured interviews with nine biology teachers of public schools in the state of Bahia (Northeastern Brazil). Analyses were conducted inductively, using categories based on the teachers' answers and carefully studying literature on science teaching. Results indicate that teachers expanded their conceptions about ethnobiology after their participation in the training course. They perceived this science as the study of complex relationships between human beings and other living beings. They also perceived the importance of exploring their students' cultural knowledge to the intercultural dialog and having ethnobiology as a tool in this process. It is concluded that ethnobiology contributes to the biology teachers' training guiding his/her practices and giving the opportunity to identify students' cultural knowledge that can be used in an intercultural dialog with the biology taught in schools; hence, it is imperative to offer training courses for teachers as a starting point.