The online auction has become an important form of e-commerce. Although using a different mode for conducting auction activities, online auctions should abide by the same code of ethics outlined in the face-to-face auction environment. Yet, ethics-related issues for online auctions have not been fully discussed in the current literature. The unique features of online auctions present an opportunity to address how ethical conduct could be supported, monitored, and enforced in an online auction environment. With technology being the backbone of online auction, information systems appear to be a useful tool in facilitating ethics enforcement. This article summarizes ethics-related issues that are particularly relevant in online auctions, and recommends a code of ethics that could be applied to online auctions. Based on this set of ethics, this article proposes a model for an information system that will support and enhance ethical conduct in an online auction environment.