The purpose of the study described in this chapter was to explore the classroom practices of teachers with varying degrees of experience in task-based language teaching (TBLT) while using a task-based syllabus. In particular, we wanted to assess the extent to which their actual classroom practices are in line with the main tenets of the task-based approach. We observed four teachers as they were team teaching in pairs during a two-week summer school for adolescent newcomers with high-beginner proficiency levels of Dutch. Results indicate that the classroom practices of both teaching teams lived up to the main principles of TBLT. On the whole, the classroom practice of the more experienced team of teachers was systematically rated higher. The classroom practice of the inexperienced team was found to be consistent with three out of the five principles that were rated, namely “Promote Learning by Doing”, “Focus on Form” and “Provide Input and Opportunities to Produce Output”. However, two other principles (“Provide Negative Feedback” and “Individualize Instruction”) were virtually absent in teachers’ use of tasks. The experienced team was found to implement some of the principles during all activities, while others seemed much more context-dependent. This study may deepen our insight into the different features of TBLT, in particular regarding core and more peripheral features of TBLT. Ultimately, it can guide qualitative training of teachers new to TBLT.