This paper focuses on a comparative analysis of the fiduciary duties of directors in a close corporation in Thailand and the U.S. The author describes the legal standards for director’s conduct and protective measures established by law and judicial rules that protect directors that act honestly and in the best interest of the corporation. The paper examines concepts such as the business judgment rule, duty of loyalty and duty of care under the Model Business Corporation Act as well as under Thai law. The paper concludes with a suggestion that Thai law should give more leeway to directors in the exercise of their business judgment.