Our qualitative literature review of 31 published studies found that (a) three major approaches are used in early childhood classrooms to support children's vocabulary learning--exposing children to advanced words, providing direct word-meaning instruction, and employing mixed-method interventions; (b) these practices support children's learning of targeted vocabulary words and/or general vocabulary knowledge gains, but various methods have differential impacts on children's depth of word knowledge; and (c) theme-based multimethod interventions are the most likely approach to close the gap. Based on these findings, we suggest future research directions and discuss implications for classroom practice. (Contains 1 figure and 1 table.)