This thesis deals with the corporate communication in theory and practice. The term of corporate communications is defined here and is also analyzed how it can be applied in practice, taking Croatian petroleum company INA as an example. Corporate communication includes entire communication of any organization. Because of the position in organizational structure, sector of corporate communication manages the relationships with every stakeholder and aims to provide effective and successful public relations. It also includes internal communication, corporate public relations, market communication and investor relations. The corporate communication is very significant and necessary for success of any company. As the part of market communication, corporate publications (annual reports, sustainable development reports) are dealt with here as well. They are regulated through the legal system of the capital market and shareholders company. It is regarded as a way of transparent and effective market communication in both theory and practice. Because of all communication activities, corporate communications are responsible for the creation of corporate reputation.