This population-based study aimed to evaluate prenatal coverage according to family income in a municipality (county) in Southern Brazil. Data were collected using a questionnaire with mothers in the first 24 hours postpartum. Prenatal coverage, first prenatal consultation in the first trimester, six or more consultations, breast and colposcopic examination, routine prenatal laboratory tests according to the protocol of the Program for Humanization of Prenatal and Delivery Care (PHPN), and prenatal ultrasound increased proportionally with family income, and all were more frequent in women from the highest income quartile (p < 0.001). Despite these results, the prevalence of low birth weight did not show a statistically significant difference between the quartiles. The local health service appeared not to be very effective, since only 26.8% of the women were classified as having received adequate prenatal care according to the PHPN criteria, and care was unequal, since quality of care for women in the lowest income quartile was inferior to that of women in the highest quartile.