A language and literacy intervention was implemented in 10 Head Start classrooms. Teachers were trained in specific book reading and conversation strategies. The focus of the intervention was to train teachers how to increase opportunities for language and vocabulary development in young children. At the end of the year, children in the intervention classrooms performed significantly better than children in the control classrooms on the Peabody Picture Vocabulary Test-III and the Expressive One-Word Vocabulary Test (3rd ed.). In addition, teachers in the intervention classrooms used strategies that promoted language development during book reading and other classroom activities. Head Start teachers can be trained to implement strategies that have positive effects on children's language and literacy development.