PURPOSE: This study examined the impact of teacher use of a print referencing style during classroom-based storybook reading sessions conducted over an academic year. Impacts on preschoolers' early literacy development were examined, focusing specifically on the domain of print knowledge. METHOD: This randomized, controlled trial examined the effects of a print referencing style on 106 preschool children attending 23 classrooms serving disadvantaged preschoolers. Following random assignment, teachers in 14 classrooms used a print referencing style during 120 large-group storybook reading sessions during a 30-week period. Teachers in 9 comparison classrooms read at the same frequency and with the same storybooks but used their normal style of reading. RESULTS: Children whose teachers used a print referencing style showed larger gains on 3 standardized measures of print knowledge: print concept knowledge, alphabet knowledge, and name writing, with medium-sized effects. CLINICAL IMPLICATIONS: The convergence of the present findings with those of previous efficacy studies indicates that print referencing intervention can be used confidently as an approach for facilitating print knowledge in preschool-age children. Speech-language pathologists can serve an important role in supporting preschool educators as they use this evidence-based technique with pupils in their classrooms.