This study aimed to determine the changes in understanding about the nature of science (NOS) and conceptual values of 28 elementary science teacher candidates who engaged in the instruction of the nature and history of science (NHOS). A values scale was used to determine the values of science teacher candidates in six areas of the conceptual dimension: Theoretical, economic, esthetic, politic, social, and religious. An open-ended questionnaire in conjunction with individual interviews was used to assess participants' pre- and post-instruction NOS views. Semi-structured interviews were conducted with six science teacher candidates who were selected from the different value levels: Low, medium, and high according to the results of the value scale. In the light of results of this study, the science teacher candidates who were engaged in the NHOS instruction received the highest score from the theoretical value dimension and the lowest score from the religious value dimension. Therefore, it can be suggested that NHOS teaching influenced the value perceptions of elementary science teacher candidates. For this reason, science teacher candidates' value perception should be considered during the NHOS instruction planning and the teaching of science. Recommendations based on this study include explicitly addressing the NOS aspects in science education courses and history and NOS teaching courses to enhance science teacher candidates' views about specific NOS aspects.