A randomised controlled trial was performed at the Queen Elizabeth Hospital to compare the effects and acceptance of routine in-patient versus out-patient management of diastolic blood pressure between 90 and 100 mm Hg in pregnant women. There were no significant differences in the establishment of the diagnosis of hypertension, development of severe hypertension or proteinuric hypertension, the number of women requiring obstetric interventions, or the neonatal outcome between the two groups. Antenatal hospital stay for the in-patient group, however, was more than twice as long as for the out-patient group (difference in mean stay, 3.7 days; 95% confidence interval, 1.3-6.2). The number of hospitalisations in the in-patient group was almost four times greater than that in the out-patient group (difference in mean number of hospitalisations, 1.7; 95% confidence interval, 1.2-2.2). The two groups did not differ in their levels of satisfaction of the overall management of blood pressure. Nevertheless, a greater proportion of women preferred to choose the same type of care among the out-patient group than among the in-patient group if they had hypertension in a future pregnancy (83.7% versus 51.2%; P<0.001). More women were dissatisfied about the number of admissions than on the frequency of out-patient care (40.5% versus 16.3%; P<0.001). We conclude that in-patient care, day care, or home monitoring should be individualised.