This article discusses why early and sustained vocabulary development is important for listening and reading comprehension development and presents findings from 8 studies implemented with children of mostly low socioeconomic status in settings from day care to first grade. Program interventions were based on learning new vocabulary developed out of storybook read-alouds and not with word-reading approaches. Practitioners and researchers may find it quite useful to implement the vocabulary-learning procedures with low-vocabulary children or English language learners in their own settings. We offer a number of suggestions and implications for future research based on conversational interactions and the findings of the 8 investigations. (Contains 1 table.)