Professional Development (PD) can be a powerful lever for improving the quality of teacher-child interactions in early childhood education and care (ECEC) and teachers' feelings of support and competence. However, there is a dearth of studies examining different formats of PD and their links with workplace features. The present study aims to understand (a) different types of PD participation (structured and center-embedded) and their levels of interest of preschool teachers in four European countries (Cyprus, Greece, Portugal, and Romania), and (b) the extent to which they are associated with PD incentives and perceived support. Participants were preschool teachers from Cyprus (N = 93; M[subscript age] = 41; SD = 7.47), Greece (N = 92; M[subscript age]= 40; SD = 9.81), Portugal (N = 92; M[subscript age]= 45; SD = 9.65), and Romania (N = 97; M[subscript age] = 40; SD = 10.40). The vast majority of participants were women (95-99%). Participants reported on PD attendance -- structured (courses/seminars, conferences) and center-embedded (e.g., observation visits, peer and/or self-observation) --, levels of interest in PD; PD incentives (e.g., release from working with children; reimbursement/payment of costs); and perceived workplace support. Results from the Multi-Group Path Models showed that, in all countries, the provision of incentives was associated with increased participation in center-embedded PD, but not in structured PD. Additionally, the perceived support from their setting was positively associated with greater interest in PD. Understanding what best supports different types of PD can be critical to inform policy efforts aiming to increase PD attendance.