This study examined the decision-making processes of preschool teachers in creating developmentally appropriate practices. Five teachers of 4-year-old children in 3 private schools participated; these teachers' classrooms scored high on both the Early Childhood Environment Rating Scale and the Classroom Practices Inventory. A model of preschool teachers' decision making process was developed, consisting of three components: classroom situation, judgment, and the curriculum. Findings, including examples of teachers' thought processes, indicated that the quality of the curriculum is affected by teachers' making sense of the classroom situation, and their judgment of what is good for the children's education. Knowledge and experience are significantly related to what teachers think is good for children. The findings highlighted several issues pertaining to developmentally appropriate decision making, including: the use of knowledge about child development and learning, the notion of readiness, level of teacher involvement, source of knowledge of individual children, working with children with special needs, and insufficient knowledge about children's social and cultural contexts. Recommendations based on the study's findings include changes in teacher education and training programs. (JPB)