&NA;From the results of the Diabetes Control and Complications Trial (DCCT) and the United Kingdom Prospective Diabetes Study, there is no doubt that improved glycemic control in subjects with diabetes mellitus results in the development of fewer microvascular and neuropathic complications. How improved glycemic control and lower hemoglobin A1c levels are best achieved is a matter of debate. This review focuses on two questions: 1) What evidence‐based medicine data exist that support the use of selfmonitoring of blood glucose (SMBG) in the care of either type 1 or type 2 diabetes patients; and 2) Does the number of SMBG tests per unit time beneficially influence glycosylated hemoglobin or other measures of diabetic control? A review of the available data demonstrates that there is substantial evidence to support the use of SMBG in type 1 diabetes. Although controversial, most studies do not show a benefit when subjects with type 2 diabetes perform SMBG. Properly designed and powered prospective studies are encouraged to further explore the usefulness of SMBG.