Corporate social responsibility (CSR) has become an acknowledged and well-established strategic approach in both theory and practice. A large majority of the existing literature emphasises CSR integration within larger corporations, although CSR also plays a pivotal role in small to medium-sized companies, SMEs. This study explores how four Danish SMEs have integrated CSR, and how the levels of external, internal and diagonal integration affect the qualitative and quantitative results of CSR. Whereas external CSR integration constitutes the external CSR communication and involvement of customers, suppliers and other stakeholders, the internal CSR integration is explained and measured through the level of employee involvement and the content and the effects of internal oriented CSR activities and communication. The diagonal integration is understood as integration with the business strategy.