This paper explores the factors associated with reproductive choices by HIV-positive pregnant women in two settings in Brazil, and particularly how health care providers and the local medical culture can affect these choices. Requesting and submitting to postpartum sterilization provide the focus of the analysis. The data come from a study conducted in prenatal care services in two cities, São Paulo and Porto Alegre. We employed two data collection strategies: collection of information from 427 patient records for HIV-positive women who had received prenatal care, and in-depth interviews with 60 women. While most women in both cities requested tubal ligation after delivery, a much higher proportion of women in Sao Paulo were actually sterilized, as compared to a tiny proportion of women in Porto Alegre. The local medical culture regarding sterilization and organization of prenatal care emerged as important factors for understanding the differences between the two cities.19 Suppl 2S365-76