Responsibility and sustainability are today a key part of doing business globally. However, the attention of scholars and policymakers has mainly been on large multinational enterprises, with small and medium-sized enterprises (SMEs) receiving less attention. Recent studies have noted the importance of learning for SMEs to engage in corporate social responsibility (CSR), but it is not yet known how the learning orientation of SMEs impacts their CSR, and how the development impacts the internationalization and performance of SMEs, which are research gaps that recent studies have noted. Shedding light on those dynamics is also important from a practical perspective since in most countries SMEs constitute a large majority of firms in both amounts and total employment. The present study contributes by illustrating how CSR impacts different types of performance in SMEs, and how the learning orientation of SMEs predetermines their CSR. Regression analyses conducted on an empirical sample of Finnish SMEs indicate that CSR in SMEs has an impact on certain types of performance and that their learning orientation determines their CSR. Therefore, the study contributes to the literature on responsibility and sustainability in SMEs, and to that SME internationalization, by shedding light on the antecedents and outcomes of CSR for SMEs.