Purpose Zero separation is a family-centred approach where newborns should be accompanied by their parents, regardless of the type of birth or health status. To our knowledge, few studies have described the way this approach is realized in clinical practice. This study describes situations of separation between mother/partner and newborn after birth on the labour ward, maternity ward and at the neonatal unit. Method An observation study was conducted during four months at a Swedish hospital. All caregivers at the three units were given the task of collecting the data. A semantic thematic analysis was performed with an inductive approach. Results Six themes emerged from the analysis. Two themes were common to all three units, one theme was common to two units and three themes emerged at only one unit. The themes describe various causes of separation, such as organizational and economic barriers, clinical routines, parents' own decisions, shortage of collaboration within and between units, as well as a shortage of interprofessional communication. Conclusion Our study shows that there is still a gap between the latest evidence-based knowledge of the importance of zero separation and current practice in newborn care. There is a need for continuous collaboration between all units responsible for the care of mother and newborn.