The article focuses on the identification of the concept and the role that corporate social responsibility may play in marketing communication of the companies of the financial services sector. The reflections start with an overview of the essence of corporate social responsibility, and move on to illustrate the relations between CSR and marketing communication. The author’s own research is the key part. For the purposes of this publication, an analysis of the website contents of the financial sector companies (operating on the Polish market) was conducted. The companies come from the compilation „Lista 500” of the largest Polish enterprises, published by „Rzeczpospolita” daily in April 2017 (the entities whose PKD classification – Polish Statistical Classification of Economic Activities – was specified predominantly as: financial and insurance activity, were selected). The article describes how the listed entities communicate their CSR activities via the company website. It illustrates selected areas of engagement (5 were highlighted) as well as the relationship between activities of pro-social nature and the activity in the area of marketing communication in a given industry. Moreover, it emphasises the differences in the mode of communication and the area of employing CSR activities between two dominating groups of entities on the financial market – banks and insurance companies.