School-based vocational training has been organised to support students' boundary crossing between school and work. Such training has the potential to engage students in relevant work-oriented schooling. Drawing on theories of boundary connections and symbolic resources, it is argued that school participants define and attribute quality to school-based vocational training based on their experiences and expectations of past, present, and future boundaries between school and work contexts. Empirical findings from an ethnographic study conducted at a Danish vocational school illustrate that students and teachers in some cases attribute negative qualities to school-based vocational training, whilst, in other cases, they find it difficult to define the boundaries between school and work, thus questioning the relevance and organisation of school-based vocational training in supporting students' boundary crossing between school and work. It is therefore argued that boundaries between school and work practices do not exist per se. Instead, more attention needs to be directed to the negotiations in which particular boundary connections between school and work practices are developed. This may have important consequences for the preparing of students for apprenticeship.