Traditional investing is mainly concerned with creating a financial return on investment for the investor and hence disregards other non-financial issues such as adverse environmental and societal impacts. This negligence of negative impacts in the investment process is beginning to be addressed with the emergence of environmental, social, and governance (ESG) investing, socially responsible investing (SRI), and other sustainable investing types. Therefore, this thesis aims to establish if and how large Nordic institutional asset owners integrate sustainability and ESG concerns into their respective investment processes. Moreover, a secondary goal is to determine what type of investing the current investment processes of the seasset owners resembles most. The thesis utilizes a qualitative methodology in order to gather the necessary data-points. All the information in this thesis comes from publicly available sources such as annual reports and sustainability reports. The study found that the asset owners analyzed utilize ESG integration in their investment processes. The asset owners have specific guidelines that pertain to ESG issues, and screen for non-compliance to ensure that investments with potentially detrimental effects on society are excluded from their respective portfolios. Aminority of the asset owners also utilizes best-in-class screening to identify investments with the strongest ESG performance. Hence, the asset owners, in general, are located between SRI and ESG investing on the motivation spectrum.