BACKGROUND: Discrimination in women's health care, particularly perinatal care, has received minimal attention. The aim of this study is to describe women's experience of discrimination in different models of maternity care and to examine the relationship between maternal social characteristics and perceived discrimination in perinatal care. METHODS: A population-based postal survey was mailed 6 months postpartum to all women who gave birth in two Australian states in September and October 2007. Perceived discrimination was assessed using a five-item measure designed to elicit information about experiences of unequal treatment by health professionals. RESULTS: A total of 4,366 eligible women completed the survey. Women attending public models of maternity care were significantly more likely to report perceived discrimination compared with women attending a private obstetrician (30.7% vs 19.7%, OR 1.79, 95% CI 1.5-2.1). Compared with women reporting no stressful life events or social health issues in pregnancy, those reporting three or more stressful life events or social health issues had a twofold increase in adjusted odds of perceived discrimination (41.1% vs 20.4%, adj OR 2.27, 95% CI 1.8-2.8). Young women (< 25 yr) and women who were smoking in pregnancy were also at increased risk of experiencing perceived discrimination. CONCLUSIONS: Discrimination is an unexplored factor in how women experience perinatal care. Developing approaches to perinatal care that incorporate the capacity to respond to the needs of vulnerable women and families requires far-reaching changes to the organization and provision of care.