This research explores two ongoing professional development (PD) modalities for early childhood teachers and their effect to teachers' performance. We compare training, teacher study groups and a combination of both to a control group in the Albanian preschool context. We aimed to obtain m?r? c?mpl?t? understanding ?f different fac?ts ?f th? ongoing professional development ?f ?arly childh??d t?ach?rs and its p?t?ntial impact ?n program quality and children's d?v?l?pm?nt in different ?arly childh??d s?ttings, especially in countries of low and middle income. This study has led to policy changes in m?r? ?ffici?ntly planning r?s?urc?s, not only f?r ?arly childhood t?ach?rs' PD, but t? t?ach?rs and ?th?r practiti?n?rs in th? field as well. This research has pushed for evidence-based policy reforms in teacher professionalization and career advancement in Albania.