Hypertension during pregnancy is one of the leading causes of maternal and foetal morbidity and mortality. Monitoring of blood pressure is therefore an essential part of prenatal care. Masked hypertension, where blood pressure levels are elevated at home despite normal blood pressure levels monitored in a clinical setting, may lead to cardiovascular and obstetric complications equal to those of sustained hypertension. This article discusses masked hypertension and the need for further investigation of blood pressure monitoring during pregnancy.