The Conners Early Childhood Behavior Short forms (Conners EC BEH[S]) is a screening tool that can be used to assess different behavioral risk in children. The factorial validity of the Conners EC BEH[S] was evaluated using data from a sample of Mexican American preschool-aged children in 2 economically stressed rural school districts. A total of 94 teachers (86 identified as Latinx) filled out the English version of Connors EC on 546 Mexican American preschoolers, and 453 parents filled out the Spanish version on 453 Mexican-American preschool-aged children. Our aim was to assess whether the 6-factor structures of the parent and teacher versions of Conners EC BEH[S] could be replicated with our unique sample of teachers, parents, and preschoolers using confirmatory factor analysis. Data were drawn from a larger randomized clinical trial of the effects of a shared-reading intervention on developing and accelerating young children's oral language. Results showed that the theory-based factorial structure was rather well supported in our Latinx parent and predominantly Latinx teacher samples, after adding a method factor for the reversely worded items on the empirical scales in both the parent- and teacher-completed forms (Tables 3 and 4 for method factor items). Correlations of the factor scores for Conners EC BEH[S] and the subscale scores of the preschool Social Skills Improvement System Rating Scales (Gresham & Elliott, 2008) also suggest good convergent and divergent validity. (author abstract)