Various fetal and maternal conditions are known to be associated with oligohydramnios. In general, oligohydramnios developed early in pregnancy is less common but frequently has a poor prognosis. The use of angiotensin-converting enzyme inhibitors or angiotensin receptor antagonists during pregnancy has been associated with oligohydramnios as well as growth restriction, pulmonary hypoplasia with respiratory distress, acute renal failure, cranial malformation and fetal death. Although many researchers report a use of oral hypoglycemic agents such as glyburide or metformin in gestational diabetes mellitus, but potential adverse effects of glimepiride, which is relatively recently developed, is not well known owing to the lack of clinical data, especially early in pregnancy. A 41-year-old woman with chronic hypertension and type 2 diabetes mellitus was treated with drugs including metformin, glimepiride and angiotensin receptor antagonist until approximately 20 weeks' gestations, when severe oligohydramnios was noted. After the hospitalization for bed rest, fetal surveillance, and discontinuation of the agents, amniotic fluid reaccumulated, and the infant was delivered at term. We report this case with a brief review of literatures.