Psychometric properties of the Phonological Awareness Literacy Screening for Preschool (PALS-PreK) instrument were investigated in a sample of 4,518 children. PALS-PreK figures prominently in state and federal early literacy programs as an assessment of emergent literacy skills in preschool-aged children. Exploratory Factor Analysis, Confirmatory Factor Analysis (CFA), and multigroup CFA were employed to evaluate the underlying factor structure and determine whether the identified structure was invariant across boys and girls. Results suggest that PALS-PreK effectively measures the most important precursors to successful literacy acquisition: alphabet knowledge, phonological awareness, and print concepts, with generally the same degree of accuracy for boys and girls. These results, combined with the instructional transparency of the instrument, support the educational utility of PALS-PreK as a tool for guiding instruction in preschool literacy. (Contains 1 figure and 5 tables.)