In this chapter, the authors begin with a thorough review of past entrepreneurship personality research. The authors recall the early dominance and eventual decline of personality research in entrepreneurship, but they point to renewed interest. The authors blame the decline in research interest on poor results from studies that were based on scant theory and flawed methodologies. Nine reasons for the current rebirth in interest in personality effects in entrepreneurship are offered, including prescriptions for better methodologies. Drawing on the meta-analyses and Rauch and Frese, they offer a research model to guide entrepreneurs' personality research. It includes KSAs (knowledge, skill, and ability), broad and specific traits, and action strategies, as well as environmental controls. "Old and new" personality traits are reviewed and considered in light of the entrepreneur's environment. Rauch and Frese conclude that there are small to moderate relationships between personality (high need for achievement, risk propensity, passion, innovativeness, autonomy, locus of control, and self-efficacy) and successful entrepreneurship and suggest that those who called for the end of doing research on personality traits for lack of important relationships are clearly wrong. Rauch and Frese strongly encourage Industrial & Organizational (I/O) psychology researchers to (a) use differentiating hypotheses for general vs. specific personality traits and (b) match the focus of independent and dependent variables. Further, they suggest that (c) interaction should be utilized to better explain the relation between personality and entrepreneurship outcomes. The research model presented captures a whole set of research questions, including the authors' call for better personality theory and for research that included mediation and interaction. Research questions such as "Do the Big Five personality traits matter for entrepreneurship success?" and "Do midlevel theories and interactional models offer better explanations of personality trait effects?" are embedded in the model. (PsycINFO Database Record (c) 2012 APA, all rights reserved