<p>This article discusses the notion of entrepreneurial ecosystems and proposes directions for the further development of the concept. Since the main goal of the concept is to identify factors that determine regional development, the key variable to assess the quality of an EE and the effect of respective policy measures should be a measure of regional performance. It is argued that a broad definition of entrepreneurship should be applied that includes the entire universe of new businesses (‘everyday’ entrepreneurship), and also accounts for incumbent firms. There is good reason to regard EE as a part of the regional innovation system and merge the two concepts. The paper discusses a number of open questions concerning the elements of a system and its dynamic properties. Finally, it outlines several key challenges for the further development of the concept.</p>