BACKGROUND: Hypertensive disorder of pregnancy is one of the direct causes of maternal mortality and morbidity globally. It is the leading cause of maternal mortality and morbidity in University of Port Harcourt Teaching Hospital (UPTH). Hydralazine, Labetalol and Nifedipine are generally regarded as first line drugs to lower blood pressure. Here at the UPTH, hydralazine was used but in recent times, labetalol has been introduced. Both drugs are now being used without a clear evidence of which is more effective. Thus, a large number of parturient might benefit if the drug that is found to be more effective is used extensively. OBJECTIVE: The objective of this study was to compare the efficacy of intravenous labetalol and hydralazine in lowering severe hypertension in pregnancy. The specific objectives were to determine the time it took each antihypertensive agent to reduce blood pressure, the number of doses of each drug required, the adverse maternal effects and the perinatal outcome. STUDY DESIGN: This was a randomized clinical trial; conducted in the labour ward of the University of Port Harcourt Teaching Hospital where pregnant women with hypertensive crisis were admitted for stabilization before delivery. Sixty (60) Pregnant women with sustained increase in systolic blood pressure of 160mmHg or higher or a diastolic blood pressure of 110mmHg or higher were randomized into 2 groups: GROUP A (30 pregnant women) received intravenous hydralazine 10mg slowly and repeated every 20 minutes until systolic blood pressure was 150mmHg and/or diastolic blood pressure was less or equal to 100mmHg. GROUP B (30 pregnant women) received intravenous labetalol in escalating doses of 20, 40, 80 and 80mg every 20 minutes until systolic blood pressure was 150mmHg and/or diastolic blood pressure was less than or equal to 100mmHg.