STUDY DESIGN: Data extraction from a state-wide, population-based, health-administration database of hospital admissions. OBJECTIVE: To determine the incidence of non-traumatic spinal cord injury (NTSCI). SETTING: Victoria, Australia. METHODS: All patients admitted to hospital with a new onset of NTSCI, or who developed NTSCI after hospitalization, between 1 July 2000 and 30 June 2006, were identified using a population-based database. Age and gender of NTSCI patients were recorded. RESULTS: The number of adults aged 15 years and older with NTSCI in each of the 12-month periods was 82, 111, 96, 108, 133 and 101. The average age-adjusted incidence rate of NTSCI in adults was 26.3 cases per million per year. There was no statistically significant increase in the age-adjusted incidence of NTSCI over the study period (Spearman's rho=0.35, P=0.5). The incidence of NTSCI was significantly greater than the reported incidence for traumatic spinal cord injury (chi2 (1)=19.5, P<0.0000). There was a very strong correlation between age and the incidence of NTSCI, for both men (Spearman's rho=1, P<0.0000) and women (Spearman's rho=0.98, P=0.0000). Men had a statistically significantly (chi2 (1)=13.1, P=0.000) higher incidence of NTSCI (30.5 million adults per year) compared to women (22.9 million adults per year). The average incidence of NTSCI in children <15 years was 0.7 cases per million per year. CONCLUSION: NTSCI is strongly correlated with age and is more common than traumatic spinal cord injury. The method used in this study to calculate the incidence of NTSCI can be used to monitor the anticipated increase in the incidence of NTSCI in the years ahead, and can be used to in comparative studies.