Despite the increasing prevalence of diabetes, improved understanding of the disease, and a variety of new medications, glycemic control does not appear to be improving. Self-monitoring of blood glucose (SMBG) is one strategy for improving glycemic control; however, patient adherence is suboptimal and proper education and follow-up are crucial. Patients need to understand why they are being asked to self-test, what their glycemic targets are, and what they should do based on the results of self-monitoring. Patients also must be taught proper technique and must be given specific recommendations regarding frequency and timing for self-monitoring. Situations in which SMBG is essential or should be more frequent include self-adjustment of insulin doses, changes in medications, lack of awareness of hypoglycemia, gestational diabetes, illness, or when hemoglobin A_1c (HbA_1c) values are above target. SMBG should include postprandial monitoring to identify glycemic excursions after meals, to indicate the need for lifestyle adjustments, and to provide patient feedback on dietary choices.