The present article uses two empirical studies to look at multiprofessional collaboration between teachers and other educational staff at German all-day schools. A quantitative study is used both to develop an instrument for the measurement of multiprofessional collaboration and to analyse the connections between collaborative action and characteristic features of the teaching staff. Additionally, a qualitative study throws light on the extent, challenges and evaluation of multiprofessional collaboration at all-day schools. The two studies point to the fact that multiprofessional collaboration is underdeveloped at German all-day schools as well as to future challenges for closer collaboration between teachers and other educational staff.