This study explores the outcomes of an interactive book reading intervention featuring expository picture books. This small-group intervention was delivered by four practitioners (two early childhood special education teachers and two speech-language pathologists) three times per week for 8 weeks to 6 preschool-age children (3 years 1 month to 4 years 9 months) identified with language impairment. The intervention included use of language facilitation strategies during interactive book reading and extension activities after reading for promoting children's understanding of signal words related to the sequence text structure (e.g. first, next, then, finally), academic vocabulary, and science topic knowledge related to plants (how plants grow, plant parts, plant needs). Outcomes indicated that practitioners increased their use of language facilitation strategies over the course of the intervention in both contexts of interactive book reading and extension activities. Children with language impairment made significant improvements in their receptive understanding of sequence signal words, vocabulary, and science topic knowledge from pre-test to post-test. These findings suggest the promise of a sequence text structure intervention implemented in the contexts of interactive book reading of expository picture books and extension activities for supporting the syntax, vocabulary, and content knowledge of preschool children with language impairment.