Vocabulary plays a critical role in later reading achievement of emergent bilingual children (EBC) who are learning two languages. Given emerging vocabulary intervention research for EBC, we synthesize studies on vocabulary interventions designed for preschool and kindergarten EBC to provide the cumulative knowledge on the following dimensions: (a) EBC's characteristics, (b) features of selected target words and books, (c) critical components of vocabulary interventions, and (d) the overall effectiveness of the interventions as reflected by the percentage of studies reporting a significant increase on proximal measures of EBC's target words. Through a systematic search, we identified 19 articles using experimental or quasi-experimental designs. Overall, EBC increased their knowledge of words taught through vocabulary instruction, and the use of bilingual or family heritage instructional language increased EBC's vocabulary knowledge in both languages.