We investigate the international network activity of entrepreneurial firms and its implications for the territorial boundaries of entrepreneurial ecosystems. Integrating the idea that territory and networks are distinct structures that can overlap with prior work suggesting that interorganizational networks formed by entrepreneurial firms pursuing opportunities transcend geographic boundaries, we focus on the antecedents to the international network activity of entrepreneurial firms in entrepreneurial ecosystems. We study how entrepreneurial ecosystem conditions, network embeddedness, and speed of firm growth influence the international network activity of 290 dedicated biotech firms located in four regional entrepreneurial ecosystems in Sweden over a period of 10 years. Descriptive data analyses reveal that the interorganizational networks created by the firms in our sample span territorial boundaries with more than half of all network activity involving a partner located in a foreign country. The results of a series of panel regression analyses further indicate that the conditions in the regional entrepreneurial ecosystems and firm characteristics influence the extent of international network activity. Through our work, we add to the scholarly understanding of the complex geography of entrepreneurial ecosystems. Our research highlights that the network activity of entrepreneurial firms oftentimes spans the territorial boundaries of entrepreneurial ecosystems and suggests that thinking outside the box of traditional predetermined administrative or political boundaries may inform more effective policy.