Acculturation may influence women’s perceptions of health care experiences and may explain the epidemiologic paradox, whereby foreign-born women have lower rates of adverse birth outcomes than United States (US)-born women. We evaluated the relationship between maternal acculturation and specific dimensions of prenatal interpersonal processes of care (IPC) in ethnically diverse women. Cross-sectional analysis of 1243 multiethnic, postpartum women who delivered at Kaiser Permanente Medical Center in Walnut Creek or San Francisco General Hospital. Women retrospectively reported on their experiences in seven domains of IPC during their pregnancy pertaining to communication, decision making, and interpersonal style. The primary independent variables were four measures of maternal acculturation: birthplace, English language proficiency, the number of years residing in the US, and age at immigration to the US. Generalized linear models, stratified by infant outcome, measured the association between each maternal acculturation measure and specific IPC domains while adjusting for type of health insurance, demographic, and reproductive factors. Approximately 60% of the sample was foreign-born, 36% reported low English proficiency, 43% had resided in the US <10 years, and 35% were age 20 years or older when they immigrated to the US. Over 64% of the women reported having public insurance during pregnancy. In adjusted analyses among women who delivered term and normal birth weight infants, less acculturated women and women with non-private health insurance were more likely to have higher mean IPC scores when compared to more acculturated or US-born women and women with private health insurance, respectively. In a large and ethnically diverse sample of childbearing women in Northern California, less acculturated pregnant women reported better prenatal care experiences than more acculturated and US-born women, another dimension of the "epidemiologic paradox." However, the relationship between acculturation and IPC, as reported during the postpartum period, differed according to infant outcomes.