Project-based vocational education and training (PBVET) is a way to conduct vocational education in Swedish construction programmes. The educational settings used include projects ranging from minor construction to advanced houses. Due to limited research on this kind of educational setting, it is important to further develop knowledge on affordances in a PBVET. The aim of this study is to describe and analyse teachers' perception on opportunities for teacher guidance provided in a PBVET. From this broad aim, the following research question is addressed: how do teachers view PBVET as (a) framing possibilities for their practice, (b) affecting students' learning and (c) presenting challenges in this learning environment? Adopted methods for this study are observations and interviews. Observations were made at a PBVET worksite, which were then used in stimulated recall interviews. The findings show that this PBVET affects both teachers' opportunities to perform teacher guidance as well as students' possibilities for learning. This appears to be related to the structure in this PBVET which can be seen as operating within different activity systems. Hence, an interaction between these systems is likely the most important issue that needs to be resolved when conducting vocational education as a PBVET.