To ensure a smooth transition from studies to professional careers, students' skills and attitudes are often considered of greater value than theoretical knowledge and understanding. Yet, whereas typical academic skills such as research and writing are commonly monitored and trained, generic skills such as teamwork and communication receive scant attention. At Maastricht University, we developed a portfolio to raise awareness about skills required to take full advantage of the Problem-Based Learning environment, and to initiate self-reflection by students. As such, the portfolio also provides an opportunity to engage in a more in-depth assessment of students' skills acquisition. Students assessed their skills at the start of the bachelor programme through a survey that was administered again at two later stages during the first year. Comparing data of 414 students, we provide a unique insight into skills progression in an active learning environment. Repeated measures can thus provide a first impression of the impact of an active learning environment on generic skills acquisition. While we argue that the current portfolio achieves its educational objectives, as an instrument for measurement of skills acquisition it has its limitations.