Is there a theory available, delivering a general frame of reference for research on the process of starting and managing new ventures? Scientific research on the foundation and growth of new ventures is seen as policy driven and quite poor in terms of its theoretical background. The objective of this paper is to analyze differ-ent approaches trying to give research on business start ups a theoretical setting. We refer to five theory ap-proaches, including Founder Psychology, Agency Theory, Industrial Economics, Start up-Management, and Organizational Ecology. The paper shows that New Venture Management does not lack theory in general. Some of the approaches discussed deliver valuable contributions for theoretic analyses. However, these approaches are isolated and deficient in terms of the requirements which have to be met. We conclude that New Venture Management is still in need of an overall theory which can be used as an overall frame of reference for research on the foun-dation and growth of new ventures.