Each organization, whether a private company, a public institution, an NGO or other organization, is an organization of human work. The aim of the work may be the production of raw materials or products, the provision of commercial or public services, representation of the public interest or individual groups. Organizations are emerging from these and many other reasons. The complexity of any larger organization and the number of internal and external interactions between the public, employees and executives will be observed through public relations, scientific discipline within information and communication sciences. This paper examines a part of public relations that is called internal communication. The importance and impact of internal communication is illustrated through a survey of satisfaction with the internal communication of young police officers. But before presenting the results of research and comparing them with the same earlier research, the topic was elaborated through a broader scientific framework. It is about psychological and sociological theories that form a solid foundation in the field of public relations, ie internal communication and corporate identity. The psychological aspects of the functioning of large enterprises and the problem of interpersonal relationships are mentioned. Then the theory of motivation for work and satisfaction at work was elaborated. In the whole psychological aspect, a sociological approach is indispensable, which examines the behavior of employees and executives through various examples. After the chosen theories expanded the reader's perspective, but precisely focused on the issues of this paper, the historical development of internal communication as well as a strategic and tactical role is described. Particular importance is given to the role of internal communications in the police, as well as theoretical knowledge of corporate identity, image, reputation and corporate personality and culture.