The purpose of this study was to determine the factors that influence the self-efficacy of undergraduate kindergarten teachers and kindergarten teachers to teach science in kindergarten. The research questions were: (1) To what extent, if at all, does the research participants' self-efficacy to teach science change following their academic development and professional experience in the field? and (2) What are the factors that affect, if at all, their self-efficacy to teach science in kindergarten? The data was collected via an online questionnaire, which was sent to both undergraduate kindergarten teachers and practicing kindergarten teachers. A Structural Equations Model (SEM) was used to analyze the data. The results indicated that the self-efficacy to teach science in kindergarten is dependent on several factors: (1) Children's enjoyment: The more the children enjoy the experience, the more the participants' self-efficacy increases; (2) Interaction with parents: the self-efficacy of the participants to teach science increases when there is positive interaction with the children's parents; and (3) Lecturers at the academic institution: self-efficacy to teach science increases when the participants enjoy learning, when they feel that science is relevant to children, and when they receive practical tools for teaching science. In conclusion, teaching science in kindergarten can be referred to as a system of relationships. In this system, the internal factors, the participants and the children, influence each other. At the same time, the external factors, the parents and the lecturers, also influence the teaching of science in kindergarten.