Research on entrepreneurial motivation of university scientists is often determined by quantitative methods without taking into account context-related influences. According to different studies, entrepreneurial scientists found a spin-off company due to motives like independency, market opportunity, money or risk of unemployment (short-term contracts). To give a comprehensive explanation, it is important to use a qualitative research view that considers academic rank, norms and values of university scientists. The author spoke with 35 natural scientists and asked professors and research fellows for their entrepreneurial motivation. The results of this study are used to develop a typology of entrepreneurial and non-entrepreneurial scientists within German universities. This paper presents the key findings of the study (Sass 2011).