Montessori education between ideals and practice : A national mapping of implementation and organizational conditions in Swedish Montessori preschools

International research provides increasing evidence that Montessori education can support children’s academic, social, and executive development. Despite the pedagogy’s longstanding presence in Sweden, systematic knowledge about how faithfully Montessori principles are implemented in Swedish preschools remains limited. This study addresses this gap by establishing a national baseline for implementation fidelity and by examining how organizational conditions are associated with variation in implementation. The study investigates two research questions: (1) to what extent Swedish preschools report implementing key Montessori principles, and (2) which organizational factors are associated with higher or lower levels of implementation. A quantitative survey was distributed to all identified Montessori and Montessori-inspired preschools in Sweden. Responses were obtained from 120 preschools (42 percent). The instrument included a self-assessed Fidelity_index based on validated international questionnaires and demonstrated high internal reliability (Cronbach’s α = .884). The analysis combined descriptive statistics, bivariate correlations, and regression modelling. The theoretical framework integrates Fidelity of Implementation (FOI) with NeoInstitutional Theory (NIT) to examine how external pressures shape organizational practices. Non-Affirmative Theory of Education (NAT) provides a complementary perspective for interpreting teachers’ professional judgement in navigating tensions between pedagogical values and institutional demands. The results indicate a high overall level of perceived implementation (M = 3.95 on a five-point scale). Philosophical and process-oriented principles, such as children’s freedom of choice (M = 4.59–4.69) and observation-based planning (M = 4.26), were rated highest, while structurally demanding elements, notably the three-hour uninterrupted work cycle (M = 3.22) and peer presentations by older children (M = 2.79), received substantially lower ratings. Organizational identity emerged as the strongest predictor of implementation fidelity, with Montessori preschools reporting significantly higher fidelity than Montessoriinspired units (β = –.536, p < .001). Interpreted through NIT, the findings suggest loose coupling, whereby preschools maintain alignment with core Montessori ideals while adapting organizationally challenging structures. From a NAT perspective, this pattern reflects professional judgement rather than simple non-compliance. The study provides the first systematic national mapping of Montessori implementation fidelity in Swedish preschools and demonstrates that structural and organizational conditions, rather than philosophical disagreement, constitute the primary constraints on full implementation.