The aim of the current study is to examine the perception of cultural diversity among German STEM students. Previous research has mainly focused on the attitudes towards gender in the STEM field. This study undertakes an innovative approach and explores the opinions of German STEM students with and without a migration background on cultural diversity and educational barriers. To test this, we conducted semi-structured interviews with 90 STEM students from two German cities. The data was analysed with a qualitative content analysis. The results show that both students with and without a migration background are to a large extent unfamiliar with the topic of cultural diversity. Most STEM students think that cultural diversity has a positive impact on work performance. Some of the barriers which students with a migration background face are unfair university structures, lack of support in the educational system, challenges of cultural adaptation, and insensitivity or hostility from host-culture members. This study shows the need for a more inclusive university culture in the STEM field. It also emphasizes that diversity trainings can successfully prepare students for intercultural experiences.