BACKGROUND: It has been estimated that half of all cancer patients should receive radiotherapy during the course of the disease. Actual Radiotherapy Utilization (RTU) rates are usually lower than the optimal rates. METHODS: Data were collected from all radiotherapy departments (RTD) in New South Wales (NSW) and the Australian Capital Territory (ACT) for the period 2004-06 and were linked to Central Cancer Registries. Geographic Information System (GIS) software was used to calculate road distance between patient residence and the closest RTD. Patients were excluded from the study if their nearest RTD was outside NSW. RESULTS: The overall RTU rate was 26%. The RTU rates decreased with increasing travel distance from patient residence to the nearest RTD (p<0.0001). Multivariate logistic regression shows that male gender, younger age and shorter travel distance were significantly associated with receiving radiotherapy. Patients were 10% less likely to receive radiotherapy for each additional 100 km distance from the nearest RTD (p<0.001). CONCLUSIONS: There was a statistically significant reduction in radiotherapy access with longer road distance between patient residence and radiotherapy department.