The purpose of this study was to examine beliefs of early childhood teachers about their readiness for teaching science, technology, engineering, and mathematics, with a focus on testing for heterogeneity of such beliefs and differential effects of teacher-related factors. The results from latent class analysis of survey data revealed two latent classes of teachers, not known a priori, with significant differences in levels of teachers' beliefs about readiness to teach science, technology, engineering, and mathematics. The teachers' teaching experience and their awareness of the importance of science, technology, engineering, and mathematics and potential challenges in teaching science, technology, engineering, and mathematics played a differential role in the classification of teachers into latent classes. In addition, the analysis of two open-ended survey questions revealed several themes in the early childhood teachers' opinions about early childhood science, technology, engineering, and mathematics education. Study findings support the necessity for professional development practices that will enhance teachers' understanding of the importance of early childhood science, technology, engineering, and mathematics education, as well as their knowledge of science, technology, engineering, and mathematics disciplines and potential challenges of teaching science, technology, engineering, and mathematics. (author abstract)