This article offers insights into what characterises innovative continuous professional development (CPD) in the field of early childhood education and care (ECEC) by analysing similarities and differences from case studies of exemplary approaches to innovative CPD in Denmark, Italy and Poland. The comparative analysis focuses on four features that are particularly relevant for innovation in CPD in the field of ECEC: the social dimension of innovation as a strengthening component; the benefit of dynamic learning processes aimed at integrating theory and practice; the role of key figures in the quality of CPD; and measurements of CPD impact, outcomes and sustainability. This analysis sheds light on the effects of dynamic factors (e.g., regular team-based reflection sessions based on documentation and observation), the importance of work conditions (e.g., contractual obligations to provide time for reflection), the critical role of pedagogical leaders (coordinators, principals and head teachers, supervisors), the importance of inter-organisational networking at a local level and the facilitating role of collaboration with research institutes. 1 | I NTR OD U CTI ON This article aims to contribute to the existing debate on what characterises innovative Continuous Professional Development (CPD) in the field of Early Childhood Education and Care (ECEC) by exploring similarities and differences from case studies of exemplary approaches to CPD in Denmark, Italy and Poland. The cases were part of the CARE project (http://ecec-care.org), a collaborative project funded by the EU within the Seventh Framework Programme (FP7-SSH-2013-2) to address issues related to quality, inclusiveness and benefits (individual, social, and economic) of ECEC in 34 | This case is set in Denmark where the national ECEC context is characterised by a 98% participation rate among children between the ages of 3 and 5 (Statistics Denmark, 2015) from all cultural and socioeconomic backgrounds. It focuses on a two-year (2011-2013) in-service innovative continuous professional development (CPD) programme (VIDA) that was offered to 120 daycare institutions in four municipalities and involved 7000 children. VIDA was 36 | BOVE ET AL.The role of key figures (pedagogical coordinators, supervisors, leaders, managers) emerges as a crucial factor for innovation in CPD. In Denmark, 'managers' were trained as key figures in VIDA in order to nurture the implementation of this CPD and lead its facilitation, co-created evolution and future. In Italy, the role of the 'pedagogical coordinators' is considered the main factor in determining ECEC quality in terms of the continuity and sustainability of CPD. In Poland, 'supervisors/leaders' are viewed as 'moderators of practitioners' personal growth, rather than just suppliers of new knowledge'. Further efforts are required in order to inspire and contribute to the design of effective long-term CPD across Europe. In all three cases, leadership and key figures emerge as influential for innovative CPD across contexts. BOVE...