Is there an entrepreneurial personality, and does it appear early in life? We provide a new answer to this important question by examining traits related to Type A behavior (Aggression, Leadership, Responsibility, and Eagerness-Energy) measured during adolescence and their relationship to entrepreneurship propensity in adulthood. The results indicate that the early-life Leadership dimension is significantly associated with a higher likelihood of 1) becoming an entrepreneur and 2) being more successful as an entrepreneur, as approximated by sales.