Objective: To explore the barriers and facilitators of building partnerships in terms of the national school health education (SHE) curriculum in Greek secondary education. Setting: One large urban public secondary school, local authorities and external partners. Methods: A single case study, adopting an ethnographic approach, sought to record and explore the reality of partnerships at school level. Multilevel sampling was employed to extract one secondary school as a site for "good practice". Individual interviews, focus groups, observation and document analysis were used to build this case study of applied partnerships. Grounded theory coding and thematic analysis identified themes associated with the idea of partnerships through the corpus of textual data (verbal and written). Results: (a) The key professional in the coordinating mechanism (local authorities) lacked sufficient support. (b) Voluntary collaborations alleviate the gaps in human resources. (c) Parents' engagement was marginal. (d) Top-down imposed partnerships did not work effectively. (e) "Social" health promoters were dismissed in favour of "biomedical" partners. Conclusions: Overall an explicit trend of failure in the process of building partnerships was shown in terms of this case of SHE curriculum implementation. To explain this trend, it is necessary to engage in attempts to understand the culture and context of the case. (Contains 1 table.)