The purpose of this paper is twofold. First, it aims to identify the challenges and barriers experienced in implementing problem-based Learning (PBL) in a language program at Sultan Qaboos University in the Sultanate of Oman. Second, it proposes a working model for integrating PBL into an existing program. The research was conducted using a case study approach underpinned by design-based research principles. The proposed model came as a result of tracing the development of the program over a period of seven years with a total of 14 instructors and 2800 students. The model consists of a number of elements which include the use of hybridizing courses, the careful scaffolding of teachers and students, and the development of a PBL culture of collaboration and interdependence. Each of these elements is described from a process perspective, detailing how we attempted to implement them and how they reacted to challenges along the way. Even though the model was designed for a specific language learning and teaching c