The importance of internal communication increased within the last years, especially between sales employees. Lack of internal communication leads to loss of sales potential, decreased productivity, and unused synergy possibilities. By improving this situation a higher employee satisfaction as well as higher revenues can be achieved. The Styria Media Group AG is one of the leading media groups in Austria, Croatia, and Slovenia. Due to a decentralised organisation of the different international firms of the group, internal communication among sales employees is lacking. This leads to the fact that salespeople are not aware of products offered by other firms of the group. The group demands measures for increasing the number of international internal projects and to enhance the employee satisfaction among international sales employees. Furthermore, sales employees’ knowledge about the corporate values defined within the “Styria First Strategy” should be increased. The main target of this master thesis is the development of an international internal communication concept for the Styria Media Group AG with a special focus on international sales employees. For this purpose, a profound analysis of existing literature identified steps that have to be considered within a communication concept. Moreover, a primary market research including a qualitative and a quantitative survey were executed in order to gain insights into the current internal communication situation among sales employees. Within the practical part of the master thesis, a concept for the international internal communication is prepared based on the results of the primary research. This concept comprises recommendations for the organisational integration, the definition of communication targets, important internal target groups, the strategy definition, and the preparation of core messages. In addition, within the operational planning phase, suggestions for an international internal communication mix, an action plan, considerations for the timing of each measure, budgeting and recommendations for controlling are given.