This paper studies the impact of banks in the internationalization activities of their small and medium sized corporate clients. The study first suggests a conceptual model on the effects of the involvement of a bank in the internationalization process of small and medium sized enterprises (SME) and subsequently exams this model empirically. We argue that high levels of bank involvement produce benefits to the internationalizing SME as those financial institutions may serve as facilitators in the internationalization process. We therefore suggest that SMEs which collaborate closely with their banks in the course of their internationalization endeavors expand not only to a broader set of countries but also faster. The empirical analysis of internationalizing Swiss SMEs supports this conception: SMEs that closely cooperate with banks internationalize more successfully than their corporate peers which do not involve with banks when venturing abroad. In addition, we could observe that engaging banks has a positive effect not only on the levels of entrepreneurial orientation of internationalizing SMEs but also on their opportunity recognition capabilities. The article contributes to the body of knowledge in international entrepreneurship, especially by offering novel antecedents to the internationalization success of SMEs.