OBJECTIVE: To assess whether some demographic and practice characteristics of general practitioners (GPs) are associated with the use of bulk billing. METHODS: A cross-sectional postal survey was conducted in late 2002 with a 15% stratified random sample, based on sex and area of practice, of currently practising GPs in New South Wales. Multinomial logistic regression was used to look at GPs' characteristics associated with their self-reported use of bulk billing. RESULTS: Of the 494 GPs who participated in the study, 44% bulk billed for all patient consultations, 34% for selective patients, while 22% did not bulk bill for any patient. Multivariate analysis revealed that GPs practising in metropolitan areas were six times more likely to bulk bill for all patients compared with GPs in rural areas (OR 6.7, 95% CI 3.8-11.9). Overseas-trained GPs were twice as likely to bulk bill for all patients compared with locally trained GPs (OR 2.3, 95% CI 1.2-4.3). The likelihood of bulk billing for all patients also increased with an increase in GPs' caseload. CONCLUSIONS: This paper discusses some of the policy and programmatic implications of the changing pattern of bulk billing. Special efforts are needed to provide increased practice support for GPs in rural and remote areas in order to ensure affordable and accessible GP services.