In this paper, we explore the role of employee general and specific human capital for the accelerated internationalization of small and medium-sized companies (SMEs) in the context of Belgium, an innovation-driven economy. More specifically, we look at the effect of employee education (general human capital) and training (specific human capital) and suggest a threshold point, after which additional firm investments in human capital become less productive. We test our ideas using a unique dataset of all manufacturing SMEs in Belgium which internationalized between 1998 and 2005 and followed a strategy of accelerated internationalization (n = 2633). Findings indicate a significant curvilinear (inverted U) association between general human capital (education) and the company’s degree of internationalization, while specific human capital (training) is not significantly associated with the degree of internationalization. Theoretical and practitioner implications are discussed.