Information on the signs and symptoms of the hypertensive disorders of pregnancy was collected for over 10,000 pregnant women as part of the Jamaican Perinatal Study. The women in the study comprised all those living in Jamaica who delivered singletons weighing more than 1000g after 27 weeks gestation during the months of September and October 1986 (n=10,185). In this population the incidence of antenatal diastolic hypertension was 10.4 por ciento , the incidence of antenatal proteinuric pre-eclampsia was 4.0 por ciento and the incidence of eclampsia was 7.1 per 1000. Risk factors for developing antenatal diastolic hypertension included primiparity, maternal age over 30 years, abnormal weight gain during pregnancy, a history of prior hypertensive disorders of pregnancy and the maternal region of residence. Risk factors for developing proteinuric pre-eclampsia were maternal age over 25 years for primiparae and maternal age over 35 years, abnormal maternal weight gain and a history of hypertensive disorders of pregnancy in multiparae. These results are compared with those from the WHO Collaborative Study on the Hypertensive Disorders of Pregnancy.