The purpose of this research is to comparatively investigate the efficacy levels of pre-service science (Science, Biology, Physics, and Chemistry) teachers enrolled at the Undergraduate Program of Science Teacher Education and Pedagogical Formation Program. A total of 275 pre-service teachers who were studying in different programmes in the Faculty of Education, Ömer Halisdemir University composed the study group of the research in which the general survey model was used. "Teachers' Sense of Efficacy Scale" developed by Tschannen-Moran & Hoy (2001) and adapted to Turkish by Çapa, Çakiroglu & Sarikaya (2005) was used as the data collection tool in the research. As a result of the study, it was concluded that pre-service teachers' level of professional efficacy was high. In addition, it was determined that while pre-service teachers' level of professional efficacy did not significantly differ based on gender, their efficacy showed differences depending on the program they were studying at and their active teaching status.