Are there conflicts caused by cultural and ethnic mixed school students? If so, what are they and how do pupils and teachers deal with it? There is not much known about problematical social issues in school life, especially when it comes to the area of social integration and the related problems. This topic is current and a sensitive issue within the general public and there is a strong demand for research in the field. This thesis focuses on general problems in the field of social integration and delivers a detailed analysis of the situation in German schools today. One of the main points is the differences between the different cultural and ethnic groups with regards to their social behaviour, related problems in school and the external influences affecting their character. The first part offers a closer look at cultural variety at school and related educational theories. An analysis of German federal statistics also displays an overview of the situation in general. Then the city of Duesseldorf is used as a case study to discuss the questions and problems identified. Through a series of questionnaires, data has been collected from teachers and professionals dealing first-hand with the issues. The results are evaluated and critically discussed from a social psychological point of view.