An alternative to insert history of science (HS) in teacher formation programs is the use of concept maps (CM), which may be very useful to represent the historical elaboration dimension of science concepts, laws, and principles. This paper presents the results of a study that identifies the conceptions of pre-service physics teachers about the relationships between CM hierarchical organization and knowledge elaboration in HS. In the first stage of the research, the content analysis methodology was used to analyze and categorize the students' answers to questions concerning the relationships between CM hierarchical organization and HS. In the second stage, the answers of a different group of pre-service teachers were analyzed concerning the level of agreement with the categories previously elaborated. The students associated CM hierarchical organization with knowledge improvement, elucidation of the importance level of the concepts, and the relationships between more general and more specific contents. We point out that the use of CM in HS subjects may contribute to the pre-service teachers associating HS concepts not in a chronological way, but in hierarchical order, from the most general to the most specific ones.