In spite of the improvement of obstetric care, hypertensive disorders of pregnancy have continued to emerge as the major causes of maternal and perinatal morbidity. Therefore, it is of interest to assess the effectiveness of melatonin as an adjuvant treatment in the management of gestational hypertension and pre-eclampsia in 404 pregnant women (183 taking melatonin and 221 taking standard care) in one of the tertiary care hospitals in India. Melatonin group also showed much lower incidences of serious pre-eclampsia that necessitated cesarean section (2.73% vs 8.60, p=0.014), lower rate of proteinuria (28.42 vs 37.10), and a better fetal outcome with a lower incidence of intrauterine death (4.92 vs 9.50). Melatonin supplementation is a potential adjuvant treatment that is promising to decrease the maternal and infant complications in pregnancy-related hypertension disorders.