The most common cause of end-stage renal disease in the United States is diabetes mellitus. Data from the Diabetes Control and Complications Trial (DCCT) and the United Kingdom Prospective Diabetes Study (UKPDS) demonstrated that near-normalization of blood glucose levels results in a significant reduction in the development and progression of diabetic nephropathy. The UKPDS, however, clearly demonstrated that tight control of blood pressure in patients with diabetes is associated with reductions in macrovascular disease. Hypertension is also a major contributor to the development of diabetic renal disease. It is currently recommended that individuals with diabetes maintain a blood pressure level of less than 130/85 to maximize renal protection. It is essential that health care practitioners are aware of the importance of assessing early evidence of renal disease such as microalbuminuria and monitoring the progression of nephropathy. This article reviews current guidelines for the management of hypertension in patients with diabetes. In particular, the rationale for the use of the major pharmacologic therapies available for the treatment of hypertension is explored.