The board of directors plays a vital role in determining a company's success or failure. However, there is always a risk of directors engaging in intentional fraud or inadvertently failing to fulfill their legal duties, resulting in losses for companies and shareholders. This thesis aims to shed light on the regulations governing directors' duties in Vietnam, focusing on joint stock companies. However, throughout this thesis, a large portion of the content applied the comparative method to compare laws and regulations regarding directors' duties in Vietnam with other countries' equivalents. Therefore, readers, even from common law or civil law countries, may all relate to their countries' laws and understand how Vietnamese law differs from their countries' laws in the research object. Additionally, the thesis aims to highlight the deficiencies in the legal framework regarding directors' duties under Vietnamese law by analyzing and comparing it with other legal systems. The content scope will encompass directors' duties in joint stock companies in Vietnam and their equivalents in other countries, including both common law jurisdictions such as the United Kingdom, Australia, Canada, and the United States, and civil law jurisdictions such as Germany, France, and China.