It is widely acknowledged that among all determinants of employment outcomes, leadership is viewed as an important predictor with a central role (Carli, 1990). It has been long held within the humanistic management perspective that different types of leadership style eventually are leading towards different outcomes. In this era of globalization, the role of leadership in determining the internalization pathways for the company is even more crucial. Due to many environment changes, companies decide to inject a new perspective into their management styles. The issue of globalization for example, has lead many companies to divert their focus to the issues of sustainability. This paradigm shift requires management to solicit the subordinates’ inputs in decision making and/or allow them to ensure that the management receive a warm support from the employees which is embarking to the sustainability journey, it actually begin from the internal groups. Thus, this paper discusses the leadership style of senior manager in medical wastes business in Indonesia. By using the qualitative approach with case study method, there were 13 semi-structured interviews with 35 questions based on the topic used to investigate the role of leader’s leadership styles. Later, all data was transcribed and coded systematically. Based on the results of the interviews, the case analysis is presented, thus at the end, this paper will conclude by recommendations for management of PT Bunga Mawar.