Research into teacher professional development (PD) highlights the importance of scrutinizing features that make PD effective. While PD effectiveness is investigated in high-income countries, exploring the landscape of PD in low-income countries undergoing paradigm shifts in education is substantial as it may engender new perspectives or confirm existing stances on PD effectiveness. This qualitative study explored the perceptions of sixteen EFL teachers from Kosovo who attended a 100-hour professional development program. Interviews, reflection accounts, feedback forms and an external report were used to explore teacher views on, firstly, the effectiveness of the PD in developing professional knowledge and skills and, secondly, the relevancy of the PD to their capacity building. Data revealed that teachers found the PD relevant due to the new knowledge and skills they acquired which led to a change of classroom practice and beliefs. Teachers disclosed that the most relevant aspects of the PD program were the content, scaffolded learning, collaboration opportunities and high-quality trainers.