An Early Childhood Ecology Scale (ECES) was developed by the authors to discern the ecology of classrooms serving young Mexican American, Latino children. Another purpose of the ECES was to assist teacher candidates with engaging in self-assessment and observing a classroom’s ecology. While other instruments exist that assess the learning environment, these instruments often do not consider the role of language and culture of linguistically and culturally diverse children. Moreover, other instruments do not have a specific reflective purpose for teacher candidates. The authors constructed Likert items initially using Weinstein and Mignano’s (1993) guiding questions for designing an early childhood environment; items addressed (a) security and shelter, (b) social contact, (c) symbolic identification, (d) task instrumentality, and (e) cognitive, social, and emotional growth. Since the intent of the measure is to assess the ecology of classrooms in which the majority of the population is Latino, mostly Mexican American, the authors also included items that reflected the native language and cultural aspects of the classroom as part of the culturally responsive ecological framework. Essentially, the constructs measured on the ECES are a synthesis of theories and knowledge considered key in the preparation of early childhood teachers. (author abstract)