Teachers’ positive attitudes and high self-efficacy beliefs are regarded as central conditions for a successful inclusive education. This article examines whether attitudes and self-efficacy beliefs towards inclusive education of student teachers are related to basic knowledge about inclusive education and to inclusion-related experiences. The sample includes student teachers for secondary schools; n = 197 in the first study year and n = 279 in the third study year. The results indicate that the inclusion-related attitudes and self-efficacy beliefs are generally neutral to positive. Latent regression analyses point to the importance of personal inclusion-related experiences for attitudes and the importance of knowledge about inclusion for self-efficacy beliefs; however, only in the subgroup of advanced students and not among students at the beginning of their studies. The results can be used to generate impulses for teacher training by identifying easily changeable factors (personal inclusion-related experiences for attitudes and the importance of knowledge about inclusion) that are important for the development of inclusion-specific attitudes and self-efficacy beliefs.