Closing the vocabulary gap for young children at risk for reading and language delays due to low socioeconomic status may have far reaching effects, as the relationship between early vocabulary knowledge and later academic achievement has been well-established. Vocabulary instruction for young children at risk for reading and language delays during classroom play is understudied, but appears to be a useful context for such interventions. A multiple probe design across behaviors replicated across participants was conducted to evaluate the effects of Enhanced Milieu Teaching (EMT) techniques embedded in play sessions on target vocabulary word acquisition for preschool participants. Participants acquired target word sets in an average of 14 sessions, which, in addition to a book with target vocabulary, included interventionist's use of the words in conversation and prompts to use target words in play routines. Implications for vocabulary instruction during play and future research are included.