This paper uses social comparison theory to explore the effect that the average size of established businesses at the regional (provincial) level may have on start-up size. It is argued that established entrepreneurs at the regional level become referents of new entrepreneurs, influencing not only the decision to become entrepreneurs but also the characteristics of the new venture, such as its initial size. Specifically, the greater the average size of established businesses at the provincial level, the bigger the start-up size of new ventures. This paper further considers how this effect is moderated by two key individual level variables: knowing an entrepreneur personally (i.e., close social referent), and being the owner and manager of an existing business (i.e., past entrepreneurial and managerial experience). Predictions are tested using data that combine individual-and provincial-level information in Spain over the period [2008][2009][2010][2011][2012][2013][2014]. The results show the positive relationship of the average size of established businesses on new venture start-up size, and that this effect decreases when the entrepreneurs have previous entrepreneurial experience.