Hypertensive disorders of pregnancy (HDP), including pre-existing hypertension, gestational hypertension, and preeclampsia, further complicate already high-risk pregnancies in women with diabetes mellitus (DM). Women with both pre-existing and gestational diabetes are at increased risk for HDP, leading to higher maternal and fetal morbidity. Further, particularly in diabetic women and women with a history of gestational diabetes, HDP significantly increases the risk for future cardiovascular events. For clinicians, women with hypertension and diabetes during pregnancy pose a management challenge. Specifically, preconception management should stress strict control of glycemia, blood pressure, and prevention of diabetic complications, specifically nephropathy, which specifically increases the risk for preeclampsia. During gestation, clinicians must be aware of potential maternal and fetal complications associated with various anti-hypertensive therapies, including known fetotoxicity of ACE inhibitors and ARBs when given in the 2nd or 3rd trimester, and the risks and benefits of expectant management versus delivery in cases of severe gestational hypertension or preeclampsia. Indeed, diabetic women must be followed closely prior to conception and throughout gestation to minimize the risk of HDP and its associated complications. J Clin Hypertens (Greenwich). 2011;13:275–284. © 2011 Wiley Periodicals, Inc.