Professional development is an essential element in teachers' growth, and subsequently, students' success. Moreover, teachers' sense of motivation and their sense of organization citizenship behavior are factors that can greatly benefit organizational success by empowering teachers and increasing workplace productivity. The purpose of this study was to examine how professional development could increase teachers' motivation and their organizational citizenship behavior. This study was a qualitative case study with descriptive statistics, which studied 28 teachers employed at two international kindergartens in Shanghai, China. The study was structured in two phases with subject area professional development opportunities offered between the two phases. In each phase, participants completed two surveys with a total of 96 Likert-items regarding their organizational citizenship behavior and sense of motivation. Eleven participants also shared their ideas in semistructured interviews. The interview transcripts were examined using the tenets of thematic analysis as set forth by Braun and Clarke (2008). Triangulation of the results indicated that professional development can increase teachers' organizational citizenship behavior and motivation if five overarching categories are fostered in the workplace; namely, clear communication, collaborative opportunities, value and recognition, professional development expectations, and incentives. The limited number of participants, a narrow population scope, and the researcher being an insider researcher at one of the participating schools were acknowledged as limitations for this study. For future studies, the researcher recommends widening the participant pool, reducing the quantitative portion of the study, and expanding the length and depth of the professional development opportunities. It can be concluded from the study that a school climate that fosters the five categories of communication, collaboration, value, professional development, and incentives while also offering specialized and relevant professional development can increase teachers' motivation and organizational citizenship behavior, leading to greater job satisfaction and a more productive workplace.