This article draws upon prior research and theory on the legitimacy threshold that suggests entrepreneurs in start-up ventures will likely employ proactive strategies to gain initial legitimacy with key stakeholders. We argue that these strategies may sometimes include questionable ethical behaviors, including telling legitimacy lies—intentional misrepresentations of the facts. Based on a review of literature on ethical decision making, we then apply two common ethical frameworks to explore the ethical boundaries of what may or may not be acceptable behavior in seeking legitimacy. We conclude the article with some specific guidelines for start-up entrepreneurs.