Placenta previa is one of the common causes of third trimester obstetrical hemorrhage and the latter is an important cause of maternal mortality specially in developing countries. The aim of this study was to determine the frequency of placenta previa and related factors in pregnant women attending emergency maternity centers of Kerman during 1998. 1560pregnants with gestational age of 28 weeks of more were studied. Data on maternal age, parity, gravidity, blood group, gestational age, clinical presentation, history of previous cesarean section and abortion and perinatal mortality within 24 hours of delivery were analysed due to placenta previa. Only 15 had placenta previa according to the sonographic reports. Maternal age, gravidity and parity had relationship with placenta previa and with increasing these factors the prevalence of placenta previa was increased. Gestational age had also significant relationship with placenta previa, which means more possibility of placenta previa in lower gestational age. 9 cases of placenat previa attended with chief complaint of vaginal bleeding. Statistical analysis showed that blood group B is a significant risk factor for developing placenta previa (OR= 3.8). There was no relationship between history of abortion, cesarean section and placenta previa. The prevalence of placenta previa in Kerman is slightly more than other regions of the world and its relationship with above can bear a significant effect on forecoming studies.