This study presents a theoretical and empirical analysis of how CEOs' external social networks impact on cognitive factors (strategic schemas and self-efficacy in opportunity recognition – SOR) to affect strategic flexibility and organisational performance. The research question was addressed using LISREL analysis, and the model was tested using data obtained from 203 Spanish organisations. We show that large but not strong networks impact positively on strategic flexibility. However, both types of network significantly influence CEO cognition (strategic schemas and SOR), which in turn encourages strategic flexibility. Moreover, the influence of strategic schemas on SOR is quite high. These considerations of how external social networks impact on strategic flexibility through the mediator role of CEO cognition extend previous research in this field. We derive inductively a model of entrepreneurial decision-making, explaining how external social networks may make a positive impact on strategic flexibility and performance, depending on their composition and CEO-specific social and cognitive factors. Our evidence reveals the combined nature of decision-making modes to respond flexibly to their evolving environments.