This paper reports on a longitudinal mixed methods evaluation study on the acquisition and development of mathematical pedagogical content knowledge (MPCK) of future teachers at several German universities. The study is a German supplementary study to the international comparative TEDS-M 2008 study. Besides the pedagogical content knowledge that was longitudinally surveyed using instruments relating to TEDS-M 2008, the study examined additionally, in qualitatively-oriented interviews, what individual perceptions the future teachers have of courses on mathematics education. In the data nine different systematic perceptions could be identified that could be assigned to four different dimensions of courses on mathematics education. Through the integration of the different results the relationship between knowledge acquisition and perceptions is described, as exemplified by the cases of two future teachers. Hereby the future teachers' explanations provide an interpretive background for the development of their MPCK.