This dissertation proposes that personality is a missing link in the intention-behavior relationship that can help explain why some individuals who have entrepreneurial intentions take entrepreneurial action, but others do not. My theory is grounded in Markman and Baron’s (2003) person-entrepreneurship framework that posits individuals who have a personality that fits with the demands and tasks of entrepreneurship, and are guided by entrepreneurial intentions, are likely to enter into entrepreneurship and find success. Presumably, individuals who have entrepreneurial intentions are more likely to engage in entrepreneurial behaviors than individuals who do not have entrepreneurial intentions. To evaluate my argument, I analyze data collected from MBA alumni of a university in the Southeastern region of the United States. I collected data over two time periods with a series of hierarchal linear regressions to test the intention-behavior relationship with narcissism, psychopathy, and ADHD as the moderating personality variables. Overall, results suggest that dark personalities do influence the intention-behavior relationship. The interaction of entrepreneurial intentions and psychopathy had a positive and significant relationship with both discovery behaviors and exploitation behaviors. The interaction of entrepreneurial intentions and ADHD was also positive and significant for discovery behaviors, but not for exploitation behaviors. Narcissism did not have a significant relationship as a main effect with either entrepreneurial behavior.