Purpose: We investigated a small-group intervention designed to teach vocabulary and comprehension skills to preschoolers who were at risk for language and reading disabilities. These language skills are important and reliable predictors of later academic achievement. Method: Preschoolers heard prerecorded stories 3 times per week over the course of a school year. A cluster randomized design was used to evaluate the effects of hearing storybooks with and without embedded vocabulary and comprehension lessons. A total of 32 classrooms were randomly assigned to experimental and comparison conditions. Approximately 6 children per classroom demonstrating low vocabulary knowledge, totaling 195 children, were enrolled. Results: Preschoolers in the comparison condition did not learn novel, challenging vocabulary words to which they were exposed in story contexts, whereas preschoolers receiving embedded lessons demonstrated significant learning gains, although vocabulary learning diminished over the course of the school year. Modest gains in comprehension skills did not differ between the two groups. Conclusion: The Story Friends curriculum appears to be highly feasible for delivery in early childhood educational settings and effective at teaching challenging vocabulary to high-risk preschoolers. [This article was published in "Journal of Speech, Language, and Hearing Research" (EJ1107550).]