Objective To investigate patient, cancer and treatment factors associated with the residence of female breast cancer patients in lower socioeconomic areas of Australia to better understand factors that may contribute to their poorer cancer outcomes. Methods Bivariable and multivariable analyses were performed using the Breast Quality Audit database of Breast Surgeons of Australia and New Zealand. Results Multivariable regression indicated that patients from lower socioeconomic areas are more likely to live in more remote areas and to be treated at regional than major city centres. Although they appeared equally likely to be referred to surgeons from BreastScreen services as patients from higher socioeconomic areas, they were less likely to be referred as asymptomatic cases from other sources. In general, their cancer and treatment characteristics did not differ from those of women from higher socioeconomic areas, but ovarian ablation therapy was less common for these patients and bilateral synchronous lesions tended to be less frequent than for women from higher socioeconomic areas. Conclusions The results indicate that patients from lower socioeconomic areas are more likely to live in more remote districts and have their treatment in regional rather than major treatment centres. Their cancer and treatment characteristics appear to be similar to those of women from higher socioeconomic areas, although they are less likely to have ovarian ablation or to be referred as asymptomatic patients from sources other than BreastScreen. What is known about this topic? It is already known from Australian data that breast cancer outcomes are not as favourable for women from areas of socioeconomic disadvantage. The reasons for the poorer outcomes have not been understood. Studies in other countries have also found poorer outcomes in women from lower socioeconomic areas, and in some instances, have attributed this finding to more advanced stages of cancers at diagnosis and more limited treatment. The reasons are likely to vary with the country and health system characteristics. What does this paper add? The present study found that in Australia, women from lower socioeconomic areas do not have more advanced cancers at diagnosis, nor, in general, other cancer features that would predispose them to poorer outcomes. The standout differences were that they tended more to live in areas that were more remote from specialist metropolitan centres and were more likely to be treated in regional settings where prior research has indicated poorer outcomes. The reasons for these poorer outcomes are not known but may include lower levels of surgical specialisation, less access to specialised adjunctive services, and less involvement with multidisciplinary teams. Women from lower socioeconomic areas also appeared more likely to attend lower case load surgeons. Little difference was evident in the type of clinical care received, although women from lower socioeconomic areas were less likely to be asymptomatic referrals from other clinical settings (excluding BreastScreen). What are the implications for practitioners? Results suggest that poorer outcomes in women from lower socioeconomic areas in Australia may have less to do with the characteristics of their breast cancers or treatment modalities and more to do with health system features, such as access to specialist centres. This study highlights the importance of demographic and health system features as potentially key factors in service outcomes. Health system research should be strengthened in Australia to augment biomedical and clinical research, with a view to best meeting service needs of all sectors of the population.