A review of literature on entrepreneurship reveals that most researchers adopt a uni-dimensional approach to explain the phenomenon. This approach, however, has failed to offer consistent explanation of the phenomenon, especially of pioneering-innovative (PI) entrepreneurship. This paper attempts to build a psychological model for the emergence of PI entrepreneurship so as to fill the existing theory-gap. It is a multi-dimensional model based on the following variables : (1) desire for autonomy, (2) optimism, (3) PI motive, (4) creative ability, (5) availability/adequacy of resources and opportunities, (6) achievement motive and (7) managerial skills. The sensitivity of these variables within the model is demonstrated and propositions are made about the critical variables required for the start-up and successful management of different types of ventures, namely, PI ventures, import-substitution ventures, imitative ventures and 'self-employment' ventures.