Background: For decades, CSR has been a central issue in the academic literature regarding how corporate, social and environmental responsibility affects investment. According to the literature, continuing to invest in CSR activities can be seen as a global trend and the opportunities it can generate continue to receive attention among most of the world's largest economies. Despite the level of popularity of CSR among various practitioners, researchers have still not reached a unified perspective on whether CSR actually improves companies' financial results and thus creates value, but also how to value sustainability aspects in the acquisition process.

Purpose: The purpose of the thesis is to create an understanding of how the acquirer handles sustainability aspects in acquisitions and investments.

Method: The thesis has been carried out via an interview study where the acquirer within M&A has been the primary main focus. The thesis has adopted a qualitative research strategy with semi-structured interviews. The method describes how the collection of the empirical material has been carried out.

Conclusion: The acquirer's corporate strategy affects the management and valuation of sustainability aspects within the M&A process. If M&A is an additional value driver, sustainability aspects are handled after a completed M&A transaction. If, on the other hand, it is an investment company, the aspects are dealt with on an ongoing basis. The target company should have a strong financial background and well-functioning management, as this is important to be considered actively working with the sustainability aspects. The thesis also demonstrates the lack of complete information and tools regarding sustainability aspects. This is something that is still being developed, which makes it difficult to evaluate sustainability at present. Instead, they act based on a future growth opportunity.