In this article, the author presents a study which focused on some of the gaps in current knowledge about vocabulary acquisition from storybook reading. First, the study examined the effects of storybook reading on the vocabulary acquisition of 4- and 5-year-olds. Second, the study not only employed repeated readings of stories but also employed the use of rich explanations of target words during the reading. Third, it contributes to knowledge of vocabulary acquisition of second-language learners because it examines ESL preschoolers' English vocabulary acquisition. Next, it examined not only the role of initial L2 vocabulary knowledge to vocabulary acquisition but also the role of initial L1 knowledge to second-language vocabulary acquisition. It utilized many storybooks to assess children's vocabulary acquisition and examined storybook reading in a time frame which reflects the typical or natural experience of repeated readings. Finally, it examined a number of variables for their contribution to vocabulary acquisition from storybook reading, including initial vocabulary knowledge in both languages, home reading practices, age, gender, and treatment. Furthermore, the study asks the following research questions: (1) Are rich explanations helpful to ESL preschoolers' acquisition of sophisticated vocabulary from storybooks? (2) Does initial L2 vocabulary level contribute to children's target vocabulary acquisition? (3) Does initial L1 vocabulary level contribute to children's target vocabulary acquisition? (4) Which of the following variables account for the variance in ESL children's English vocabulary acquisition from storybook reading: treatment, initial L2 level, initial L1 level, home reading practices, age, and gender?