The objective of this study is twofold: first, to investigate how organizations encourage factors that have an impact on employees’ entrepreneurial behavior from employee’s perspectives and experiences; and second, to discover how and why employees behave entrepreneurially within the organization. A case study method is considered as an appropriate approach to scrutinize intrapreneurial behavior because it principally concentrates on an investigation into a contemporary organizational phenomenon and context concerning entrepreneurial activities in-depth within its real situation. In data collection, an Asian multinational retail company was selected. Semi-structured interviews were carried out with 24 executive-level employees who had been working in various departments for more than 5 years. Each in-depth interview lasts for a duration of 40 to 60 minutes. The results reveal several understandings into the combination of individual-level and organizational-level factors that promote the intrapreneurial behavior and activities of the established firm in the context of Thailand. In this regard, six factors have been found as the key determinants that make an impact on innovativeness, proactiveness, and risk-taking behaviour of the employees. Those factors are personal preference, organizational stability, management support, compensation, reward system, teamwork, quality of relationship with colleagues, work autonomy and the quality of relationship with the superiors.