Merging the literatures of how to enhance young children's vocabulary development and how to improve learning through play, this study tested two vocabulary teaching protocols on at-risk preschool children: Explicit Instructional Vocabulary Protocol (EIVP) and shortened EIVP and a play session (EIVP + Play). From a group of 118 lowest-performing students, 49 children were divided into two groups and received either EIVP or EIVP + Play twice weekly in thirty-minute tutoring sessions over the course of four months. A total of 64 words were taught. The results revealed that children who received the EVIP + Play showed more growth on both receptive-vocabulary and expressive-vocabulary measures and that more children who received EIVP + Play met the benchmark on the receptive vocabulary, measured by their performance on the Peabody Picture Vocabulary Test (PPVT III). Additionally, children in the EIVP + Play group showed a steeper growth trajectory on the curriculum-based measurement tool. The premise and importance of guided play in literacy learning is discussed, and further research is suggested.