As increasing internationalization implicates considerable changes as for example foreign assignment and multicultural teams, employees have to be prepared for these changes accordingly. The principal objective of this thesis is to find out the main demands on personnel development in connection with internationalization of business. At the beginning, the term internationalization is defined, and the boundary conditions, the reasons for internationalization and the modes of internationalization are explained. As employees contribute essentially to the implementation of an internationalization strategy, the meaning of internationalization for employees is discussed as well. Furthermore, culture and intercultural competence as main influences on the success of internationalization are focused. Therefore a definition of the term culture is given first. Afterwards, culture and cultural differences are analyzed with the help of the culture models of Hofstede and Schein. As well, the term and the dimensions of intercultural competence are shown, and their meaning in connection with international activities is described. In the next step, the focus lies on personnel development, which is an important task to prepare employees. The different fields of personnel development and the interplay of personnel development, organizational development and personal development are discussed. The influences on personnel development, its tools and its specifics in an intercultural context are considered too. As intercultural training is the most important personnel development tool, it is regarded in detail. After a definition of the term, the objectives of an intercultural training are focused, and the contents and methods of an intercultural training are clarified. With the help of these two characteristics, intercultural trainings are classified in four types, which are described in detail. This shows, how employees can be encouraged in developing intercultural competence.