In cases of suspected non-accidental injury, the possibility of brittle bones due to osteogenesis imperfecta (OI) may arise. OI is an inherited disorder due to gene mutation. A case is presented of a child who was initially diagnosed with OI following a skull fracture. However, the child later presented with multiple fractures and soft tissue injuries which were considered to be due to non-accidental injury. Where a bone fragility disorder has been suspected in a child, it can be difficult to distinguish between accidental and non-accidental injury. Multidisciplinary case review, taking into account the social history and any concerns professionals have about the family, is considered invaluable in informing a difficult diagnosis. It is imperative that all professionals draw on their own knowledge and expertise to appropriately challenge diagnoses without causing conflict. Professionals should be willing to challenge the exclusion of non-accidental injury when such exclusion is not evidence-based. For the future welfare of the child and family, it is important that the diagnosis be correct. Figures, tables, and references