This chapter examines the importance and development of competive advantages amongst ecopreneurial firms by examining 64 enterprises in Germany, Austria and Schwitzerland. The chosen enterprises fulfilled two prerequisites: they have made solutions for ecological problems to their core business, and they are also market leaders in special segments for ecological products or services. Five factors were found to account for the competitive strategies of ecopreneurial firms: "reputation", creativity", exclusivity", "nearness to customers" and "technical competence". It appears that reputation and credibiltiy are especially important for green business striving to develop a competitive market niche themselves.