The language immersion approach of the Intercultural Montessori School (Oak Park, Illinois) for children aged 2-6 years is described and discussed. An introductory section gives background information on early work with immersion by Maria Montessori, a personal experience leading to the school's establishment, and the response of language and education professionals, the public, and parents to the concept of preschool immersion. Subsequent sections discuss common patterns in the students' language learning experience at the school and the developmental stages the learners went through as the experiment progressed: pre-production; early production; speech emergence; and intermediate fluency. Anecdotal information about specific students and events are used for illustration. Observations about comprehensible input and the Montessori manipulables, whole language, and other instructional strategies are included. Specific recommendations are made for content and classroom procedures in early childhood immersion, based on this experience. The paper concludes with reflections on the potential of this environment for development of bilingualism. Contains 29 references. (MSE)