Ambition, an individual trait that we show to be empirically distinct from the Big Five dimensions of personality, has been under theorized and researched as an important determinant of both career success and unethical behavior. We argue that the specific goals or focus of ambition, as well as the level of general ambition, are important. Study 1 used a large sample of working adults and found that general ambition and extrinsically-focused ambition were associated with a willingness to engage in political behavior and career success. Study 2 surveyed a second sample of working adults and found that extrinsic ambition was associated with an increased tendency to misrepresent qualifications when applying for a job. In Study 3, using four distinct scenarios, we found that extrinsic ambition was associated with people's willingness to engage in unethical behavior. The data make the case that ambition is an important trait useful for understanding people's careers and that there are at least two forms of ambition. Moreover, like some other personal traits such as narcissism, ambition can be a double-edged sword, associated both with career achievement and being willing to take ethical shortcuts to achieve success.