Objective: This study investigated the link between socioeconomic status and unplanned dental presentations at the Perth Children's Hospital (PCH), as well as the link between the socioeconomic status of unplanned dental patients and any previous admissions to the PCH. Methods: Records of 351 unplanned visits to the PCH were collected, including reason for attendance (infection, trauma, other), the patient's residential location (suburb) and the history of any previous presentations at the PCH. The socioeconomic status of each patient was based on the Index of Relative Socio-Economic Disadvantage, divided into quintiles. Geographic information systems (GIS) were used to spatially map the residential locations of the patients with unplanned dental presentations. QGIS was used to map and geocode the data. Analysis of variance and Chi-squared tests were used to determine associations between subgroups and other variables. Results: 'Unplanned dental presentation' in this study refers to patients who present without an appointment, including by referral from the emergency department of the PCH or outside the PCH. Approximately two-thirds of unplanned dental presentation among patients from low socioeconomic groups were for dental infection, whereas the major reason for presentation among patients from higher socioeconomic groups was trauma. More than half the patients in low socioeconomic groups had at least one previous presentation at the PCH due to other medical issues. Conclusion: Children from low socioeconomic groups, or from outside of Perth, were more likely to present with dental infections, which are mostly preventable at the primary care level; these patients often presented a more significant burden to the health system. Public health interventions should aim to promote preventive oral health care, especially for children from low socioeconomic groups. What is known about the topic?: In Western Australia, the most common dental problems requiring hospitalisation among children is dental caries, and children from the lowest socioeconomic backgrounds have the highest prevalence of dental hospitalisations. What does this paper add?: Children from lower socioeconomic backgrounds were more likely to have an unplanned presentation at the only tertiary children's hospital in Western Australia due to dental infection. What are the implications for practitioners?: Improved access to public dental services, especially in low socioeconomic areas, and the development of more strategies to reduce unplanned dental presentations at a tertiary hospital are needed. [ABSTRACT FROM AUTHOR]