The association between prenatal care and infant health has been shown in many studies. Therefore, accurate information on prenatal care is required to assess the organization of preventive measures aiming at a reducing in neonatal mortality any morbidity. We retrospectively collected data on 854 pregnancies. According to a classification scheme developed by Kessner, 61.6% of women had access to adequate prenatal care. Overall, the proportion of adequate prenatal care was lower among multiparas, and in this subgroup we found a lower rate for women with base line insurance. In the primiparas subgroup we found a lower rate of adequate prenatal care for foreigners, women under 20 years or unmarried mothers, and for women without professional activity during pregnancy, besides preterm birth was more frequent amongst women in the group of prenatal care qualified as intermediate or inadequate. The frequency of pregnancy visits and the Kessner index are discussed in a literature review. The association between socio-economic indicators and prenatal care was unexpected considering the overall wealth of Switzerland. With a 6.8% infant mortality registered in 1989, this country can be considered to have one of the lowest rates in the world. These findings nevertheless suggest the way to possible additional gains by interventions targeted to specific socio-economic groups.