Many studies have confirmed that STEM education should begin in childhood, where children have a natural inclination to question, create, investigate, and explore. STEM education focuses on real-life issues, often encouraging children to work in groups and collaborate. Preschool teachers play an important role in organizing STEM education activities for preschool children. Using quantitative research methods, the survey sample includes 416 preschool teachers currently working in Hanoi, Vinh Phuc and Dien Bien provinces. The results show that three factors: support of administrators, specialized knowledge of the fields, attitude and confidence of preschool teachers have a statistically significant influence on STEM education implementation of preschool teachers. The results of this study are the basis for recommending a number of policies to promote the practice of STEM education in early childhood education.