PurposeInterprofessional collaboration and coordination are critical to developing solutions to complex problems, and many workplaces engage in coordination and collaboration across organizational boundaries. This development changes work conditions and workplaces for many people. The ethnographic study of workplaces needs to re-configure the toolbox to adjust to such changes. The purpose of this study was to explore how the ethnographic study of dispersed workplaces can benefit from the analytical concept of boundary work.Design/methodology/approachA multi-sited ethnographic study was conducted in two health promotion programs, introducing new collaborative relations across sectors and professions. The concept of boundary work was applied as the conceptual frame and introduced the diagnosis of gestational diabetes mellitus (GDM) as a boundary object.FindingsProfessional boundaries are key to understanding interorganizational and interprofessional collaborations. The ethnographic study of complex, multi-sited settings using boundary work as a conceptual framework can enrich workplace ethnographies by demonstrating how professions position themselves through framing. Such framing strategies are used to construct, defend or contest boundaries. Boundary objects may potentially bridge devices connecting people across boundaries.Originality/valueThe traditional ethnographic notion of “following” an object or a subject is difficult in a workplace environment dispersed across multiple sites and involving many different actors. This suggests that workplace ethnographies studying interorganizational workplaces would benefit from a shift in focus from place-based or group-based ethnography to a field-level ethnography of relations using boundary work as an analytical frame.