This paper offers a method for evaluating protective factors in young children at risk for emotional and/or behavioral disorders. It reviews the development, standardization, validation, and use of a new, nationally standardized measure of within child protective factors, the Devereux Early Childhood Assessment (DECA). The DECA evaluates the frequency of 30 positive behaviors and is completed by parents, preschool teachers, and child care providers. Psychometric data are provided on the standardization sample (more than 2,000 children in 27 states), scale development (resulting in establishing the four factors of efficacy, sociability, emotional regulation, and attachment), reliability (total scale reliability, internal reliability, test-retest reliability, and inter-rater reliability), and validity (criterion validity and construct validity). The paper finds that the DECA could be critically important to the primary prevention efforts within the preschool system of care. (DB)