Maintaining oral hygiene is an essential part of daily living and even in ‘healthy’ individuals this can be problematic ( Thurgood 1994 ). There is an important role for the nurse in maintaining good oral hygiene, either directly by providing oral care or indirectly by providing advice and opportunities to provide self-care ( Torrance 1990 ), thus contributing to the child's overall comfort. The nurse has a pivotal role in deciding which form of oral care to provide, this includes which implement or cleansing agent to introduce and the frequency with which it is used. Performing indiscriminate oral care not only causes physiological problems but it may also have psychological ramifications for the child. Consequently, oral care procedures must be based on sound scientific evidence, and not on tradition, anecdote or subjective evaluation. Action research was chosen as the change strategy in which to examine oral care practice on a paediatric oncology unit, and the processes involved within this are described in this paper.