In this chapter various theories and approaches to motivational research are reviewed and applied to the study of the entrepreneur. These are discussed with respect to both necessity and opportunistic entrepreneurship. Various models that integrate internal and external motivation are explored and the concept of risk is examined as a form of motivation. The role of goals and goal setting is also discussed in the motivational framework and is tied to intrinsic and extrinsic motivations. In addition, work and life satisfaction are reviewed as they impact entrepreneurial motivation with specific attention paid to career motivation. Finally, achievement motivation is discussed, not only in terms of a unidimensional model, but also in terms of a multi-dimensional model to predict the performance of firms using the motivation characteristics of the entrepreneur.