||This paper explores the addition of a sustainability curriculum in a Montessori early childhood classroom. The question that will be answered is "What factors contribute to sustainability education in the Montessori early childhood classroom, and do children's attitudes change as a result of curriculum implementation?" The setting is a Montessori school located in Utah. The participants are three- to six-year-old boys and girls, the classroom teacher, and the assistant/researcher. The theoretical framework was constructivism and systems theory. The methods used were daily observation, journaling, interviews, and survey. The findings included three main themes which were supported by sub-categories: environment, simple instruction, and learning to observe and share. In the classroom, the children worked with individual works on the shelves and participated in group discussion. Children developed a connection with nature by learning about the earth, plants, gardening, and animals. The children became active observers in the outdoor environment and developed a relationship of awareness and appreciation.