The aim of this study is to investigate the self-efficacy levels of pre-service science teachers in relation to STEM practices. For this purpose, the research was conducted during the 2021–2022 academic year with 110 volunteer pre-service teachers enrolled in the third and fourth years of the Department of Science Education at a public university. In collecting the data, the general survey model, one of the quantitative research methods, was utilized. The data for the study were gathered through a convenience sampling method. As the data collection instrument, the "STEM Practices Self-Efficacy Scale" developed by Özdemir, Yaman, and Vural (2018) was employed. The scale consists of 18 items and is structured as a five-point Likert-type scale. The Cronbach’s alpha internal consistency coefficient of the scale was calculated as .97. The data obtained from this study were analyzed using the SPSS 21 statistical analysis software. Overall, the findings of the study indicated that the pre-service teachers possessed an adequate level of self-efficacy regarding STEM practices. It is anticipated that the results of this study will provide guidance for program developers and teachers concerning the implementation of STEM education in Turkey.