The purpose of this mixed methods study was to determine the effect of professional development on teachers' perceptions of their ability to foster resilience. Secondary questions investigated the effects of school level and socioeconomic status. An exploratory multi-site case study was designed to compare the perceptions of educators from two elementary schools and one middle school from two separate school districts, one district that had presented professional development in resilience and one that had not. Thirty-six educators were asked to complete an electronic questionnaire, and twelve teachers participated in individual interviews. Additionally, a focus group interview was held in each school district. Three themes emerged from the findings: (a) understanding resilience, (b) understanding the role of the teacher and (c) understanding school environments. Narratives were presented for each of the six cases, combining quantitative and qualitative data. Analysis of data did show differences in teachers' perceptions between school levels but did not reflect a significant difference between school districts or between school environments of different socioeconomic status. The concept of fostering resilience proved to be an abstract idea accompanied by misunderstandings and embedded in unique school environments. Interpretation of the results focused on cross-case interpretations, resilience in nested systems and overcoming translational gaps. The conclusions of the study highlighted the need for extended professional development in resilience, the importance of reaching deep levels of understanding and the reasons to consider the interactions of multiple systems in each unique school environment when planning professional development in fostering resilience. The data from the study supported the critical need for professional development in resilience, with attention to the level of understanding needed to facilitate translational practices. Professional development requires ongoing and multifaceted evaluations for most effective results. The results of this study show the need for intricate and thoughtful planning when providing effective professional development that translates to daily practice. Training must be inclusive, multi-layered, long-term and targeted to the needs of the school. [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://www.proquest.com/en-US/products/dissertations/individuals.shtml.]