Nurturing, responsive relationships between teachers and young children and between children and their peers are critically important predictors of lifelong positive outcomes (Jones et al., 2015; DeLay et al., 2016; Hanish et al., 2016). By prioritizing strategies that promote and sustain these types of relationships with and between children, teachers can create a more positive classroom community. With training and coaching, teachers can successfully implement a variety of strategies that promote positive relationships with and between children (e.g., Artman-Meeker et al., 2021; Locchetta & Barton., in prep). However, few studies examine the effect of teacher implemented interventions on associated child outcomes (e.g., Hemmeter et al., 2021; Hemmeter et al., 2016). In this study, a multiple-probe across routines design was used to examine whether professional development with email coaching and a teacher's use of positive relationships strategies increase the frequency of positive child social interactions with teachers and peers. Though a functional relation was not identified between the intervention and target children's positive social interactions with adults and peers, there was a relation between the intervention and target children's average positive social interactions in two of four routines, and children's social interactions became more stable in a third routine. Additionally, increases in social interactions maintained at levels higher than baseline in one routine three months following intervention. These changes in social interactions also produced modest improvements on the TPOT-K and a subset of items on the ICP from pre- to post-test. Limitations and implications for research and practice are also discussed. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]