The duty to act for proper purposes is seldom applied and thus is not well-developed in Singapore. The aim of this article is to describe the development of the duty to act for proper purposes in other Commonwealth jurisdictions, and in the process, better understand when an exercise of a power by a director may be subject to review according to the duty. The argument is made that the duty is flexible, capable of application in a wide variety of situations and it is hoped the law as regards this duty has the opportunity to develop in Singapore.