Developing internal communication in fast-changing organizations is a current topic, which seems to exercise the minds of corporate people in different positions. Well-functioning internal communication and business success seem to be strongly linked. It motivates people, and only people who are motivated and enthusiastic about their work are able to perform well in their jobs and to secure the success of their employers. The purpose of this study was to increase the understanding of internal communications and how employees perceive it in fast-changing organizations. An understanding of internal communication and its development was searched by concentrating in selected essential internal communication areas in organizations, internal corporate communication function and internal communication channels. The focus was on fast-changing organizations due to the fact that the development of internal communication does not usually go hand in hand with other organization development and business growth but tends to drag behind. The theoretical framework was formed of internal communication in general, internal communication development, internal communication in fast-changing organizations, internal communication in different organizational areas, internal corporate communicationas a function and internal communication channels. The most valid internal communication areas were selected to be management communication, team and supervisor communication and interdepartmental communication. The theoretical framework presented the dilemmas and characteristics that can occur among the issue of internal communication development. In order to achieve the determined objectives, a quantitative study was conducted. The survey named “Internal communications at the company x” with three different forms of questions was carried out in the case company. The topic was scrutinized from theperspective of a case company and aimed to find out employees’ perceptions. The web-based survey focused on the selected issues concerning internal communication and its development. Questionnaires were sent out to the employees of the case company’s European organization and 94 responses were received. The collected data was analyzed against the theoretical framework, and with the help of analysis conclusions and managerial implications regarding this study were drawn. It was discovered that by developing these internal communication areas together, fast-changing organizations succeed better in internal communication and consequently in other operations. In fast-changing organizations, careful attention needs to be paid especially to the amount of management, supervisor and interdepartmental communication. Communication especially about company situation and financial and sales situation should be increased. Employees value open, systematic, clear and well-organized communication. Development of interdepartmental communication processes is vital in order to improve knowledge sharing across the company and consequently business performance. It is essential that all members of work community understand their responsibility to communicate. Internal corporate communications function should teach that and provide good communication tools for all employees, especially intranet, e-mail and possibilities to face to face meetings and versatile feedback sessions. Efforts to equalize communication between locations, departments and teams need to be taken.