The relevant literature reveals that school leaders are at the forefront of the endeavor for implementing policies and making-decisions with regard to the professional development of teachers. In order to plan, implement, and evaluate the appropriate programming, school leaders, especially principals, must make decisions that promote a professional development culture in the school. This research study is aimed towards exploring the decision-making processes of the principal with regard to teacher's professional development in a private sector school. The study intended to know how these decisions support teachers' professional development, engendering a culture of professional development in the school. The researcher selected tire private sector because the principals working in the private sector schools are more autonomous as compared to their counterpart in the public sector. Since the study was undertaken in a real school context, qualitative case study design best suited the feat to explore and understand the processes involved in a principal's decision-making process with regard to the professional development of his/her teachers. Qualitative data were collected through interview, observation and document analysis. A semi-structured interview guide was used to interview the research participant. Findings of the study reveal that the decision-making process is a complex and tension-stricken process. There is no specific framework or way to process professional development decisions, rather it depends on the situation and professional needs of the teachers; one size may not fit in all situations. Therefore, the principal processes the decisions with regard to professional development using various strategies and procedures according to the situation; such as, sole decision, individual-led decision, shared decision and decision through intimation. Among all these processes, the principal of the school prefers shared decisions. However, because of different situation, shared decision-making could not always be practiced, but he mostly uses shared decision-making approach as an effective decision-making process. The findings of the study have implications for the private sector schools with similar contexts to lead the decision-making processes for professional development initiatives.