German universities are obligated to guarantee a fair learning environment for students with diverse features. They also must prepare students for a highly diverse working environment. This means to develop awareness for diversity and to train intercultural competence. The present study takes an exploratory look at the extent to which diversity awareness is established among science, technology, engineering, and mathematics (STEM) students and which barriers for the academic success students with a migration background perceive. To counteract discrepancies between the current state and the need for diversity awareness at universities, it identifies areas with room for improvement regarding the dealing with cultural diversity. Structured interviews with 31 STEM students were carried out and analyzed using qualitative content analysis. The interviews revealed differences in the awareness of diversity between students with and without a migration background. Results showed that there are barriers for STEM students with migration backgrounds which potentially reduce their academic success. Those barriers result from a lack of acceptance of cultural diversity and insufficient social integration and were especially apparent in insufficient language skills, orientation difficulties, and a lower degree of social integration. On the other hand, there is a need for both students with and without a migration background to promote competence and raise awareness for diversity. Furthermore, the role of social support as a resource became apparent.