Maternal mortality in Sweden has declined steeply over the past 50 years. The reasons for this gratifying trend have been analysed. A decreasing incidence of complications during pregnancy and delivery, together with a lower case fatality rate from complications have been found to account for the major part of the reduction in maternal mortality in Sweden. This has been achieved by improvements in obstetrical and antenatal care, by the introduction of antibiotics and blood transfusion, and by a favorable shift to more appropriate ages for reproduction.