This study examines the internationalization of high technology small and medium enterprises (HTSMEs). It explores how they develop and use networks to penetrate their first foreign market relying on information collected via direct interviews with the CEOs or founders of 58 high technology small firms that operate internationally. It uses mixed methods to discuss the network building mechanisms identified — client–supplier relationships, existing personal contacts, contacts acquired by chance, and contacts acquired through specific strategies. The findings provide the basis for developing propositions for further comparative analyses of the internationalization of HTSMEs based in emerging and developed markets. The study contributes to the literature on networks, internationalization and international entrepreneurship.