Students who have to retake courses at university are often not only lowachieving, but also unmotivated and lacking self-confidence. These problems may be accentuated in large groups of repeater students. In this context, the implementation of new teaching approaches to cater for their needs is a priority. This paper reports the experience of a teaching strategy based on the implementation of flipped classroom, team-based learning, and frequent testing methodologies in large groups of students retaking a subject. The study was carried out during the academic years 2013/14 and 2014/15 at the Faculty of Economy and Business, University of Barcelona (Spain). The results reflect a significant increase in the motivation and academic performance of these students, and validate the application of this strategy in large groups.