The attention on CSR from business as well as society is currently growing, which results in an increasing trend of corporate sustainability practices of organizations. This research is specifically aimed at the banking sector because they have a widespread influence on both business and society. The main research question of this thesis is: what are the reasons for banks to engage in corporate sustainability and how are their CSR practices affected by several factors. The main findings of this thesis are that corporate sustainability practices of banks are mainly influenced by the most powerful stakeholders such as clients, employees and NGO''s. Since much is unclear about the meaning of CSR this results in different views and therefore different corporate sustainability practices. Furthermore corporate sustainability will not be pursued by the banking sector unless it leads to certain benefits. The results of this research also indicate that the attention of the banking sector for CSR is currently increasing.