All 5304 births in the hospitals of Pelotas, Rio Grande do Sul, Brazil in 1993 were studied. Neonates were examined and their mothers were interviewed regarding sociodemographic conditions, family income, reproductive health, and medical care during pregnancy. Ninety-five per cent of women received prenatal care. The mean number of physician visits during pregnancy was 7 and the majority of the women (84.7%) began visits before the fifth month of pregnancy. Women who did not receive prenatal care were from the lowest socioeconomic stratum and were mostly adolescents or over 40 years of age. Incidence of low birth weight in this group was 2.5 times that of the group with more than five visits (p>0.001). Perinatal mortality rate was 50.6/1000 in the group without prenatal care and 15.8/1000 in the group with more than five visits. With regard to utilization of health care, the study shows that twenty-five per cent of women with high gestational risk received inadequate prenatal care. The rate was less than 10% in the group of women with low gestational risk. These results suggest the need for improvement in the quality of prenatal care with special attention for mothers with high gestational risk.