The current study investigated the ratings of Estonian, Finnish, Swedish and Hungarian preschool teachers and principals regarding the professionalism of preschool teachers within a cross-cultural context. According to reports commissioned by the European Commission and OECD, the professionalism of preschool teachers is a key factor in ensuring the quality of early childhood education. The study is based on the contextual approach in the bio-ecological theory and critical ecology theory of early childhood professionalism. The research question was: what are ratings of principals and teachers regarding the professionalism of preschool teachers in interaction and family involvement, the planning of education and the evaluation of children's development, using teaching strategies and support for professional development, creating a growth environment and the development of values. Structured questionnaires were conducted, the sample consisted of teachers and principals in Estonian (174/118), Finnish (82/84), Swedish (117/96) and Hungarian (111/99) preschools. In the comparison of the results from the four countries, there were similarities between the views of Finnish and Swedish teachers and principals and between Estonian and Hungarian teachers and principals. Differences between the countries were significant and depended on the context of the individual countries. Highest mean ratings were given by Estonian and Hungarian principals and Estonian teachers to creating growth environment. Development of values was evaluated highest by Finnish principals and teachers. Swedish teachers evaluated teaching strategies highly. The statements that got the lowest evaluation rate by all interest groups were family involvement and professional development.