This article reports on the development of a concept of personal initiative (PI). Personal initiative is a work behavior defined as self-starting and proactive that overcomes barriers to achieve a goal. It is argued that future workplaces will require people to show more PI than before, and that current concepts of performance and organizational behavior are more reactive than desirable. The facets of PI are developed along the lines of goals, information collection, plans, and feedback. Personal initiative enables people to deal with job difficulties more actively, for example, with stressors, unemployment, career changes, or becoming an entrepreneur. High PI changes the work situation of employees and relates to success as an entrepreneur. Personal initiative is seen to sharpen and partly modify the concepts of reciprocal determinism, organizational citizenship behavior, innovation, entrepreneurship, work performance, intrinsic motivation, and self-regulation.