Demographic and health surveys are a useful source of information on the levels and trends of neonatal mortality in developing countries. Such surveys provide data on mortality occurring at 4–14 days of life, which is a sensitive indicator of neonatal tetanus mortality. We analyze birth history data from 37 national surveys in developing countries to assess the quality of neonatal mortality data and to estimate levels and trends in mortality occurring at 4–14 days. It is shown that mortality at 4-14 days has declined considerably during the last decade in most developing countries, concomitant with development and expansion of programs to reduce neonatal tetanus. These declines show that reductions in neonatal tetanus mortality probably have been an important contributor to the decline of neonatal and infant mortality during the 1980s.