Hypertension is one of the more serious medical problems requiring special attention during labor. Clinical midwifery data were used to determine the incidence of and risk factors for intrapartum hypertension in a low-risk population of women who received care from certified nurse-midwives. Descriptive statistics are reported for demographic and clinical variables. Nulliparity and young maternal age were two important risk factors for onset of hypertension in labor. Body mass index, weight gain in pregnancy, and advanced maternal age, however, were not predictors. The impact of cultural factors and the style of care on the modification of risk conditions warrants further investigation.