This article presents the results of a systematic review of the literature involving writing interventions in the preschool setting. The information presented is timely considering the current expectations for young children to write. Framing the empirical literature within different philosophical approaches, trends were analyzed to identify instructional strategies related to increases in emergent literacy outcomes and where gaps in the literature existed. The results from 22 intervention conditions from 1990 to 2013 indicated the overall effect size was g = 0.44, 95% CIs [0.27, 0.60], suggesting that preschool writing interventions enhanced children's early literacy outcomes. The findings also highlighted the importance of quality literacy environments and adult involvement. The findings from this article have important instructional implications for writing instruction in the preschool setting.