Objective: The aim of this study was to describe glycemic control levels (fasting plasma glucose [FPG] and glycosylated hemoglobin [HbA(1c)]) and pharmacotherapy change patterns among a cohort of patients with type 2 diabetes mellitus (T2DM) receiving various antidiabetic agents. Methods: This study, a retrospective analysis conducted from a large electronic medical record database, identified T2DM patients with >= 1 prescription for metformin, sulfonylureas, or thiazolidinediones from January 23, 1997, through March 15, 2006. The database contained medical and clinical records of patients-including diagnoses, medications, laboratory results, and physician orders-linked through encrypted patient identifiers. This study calculated the mean and median FPG and HbA(1c) values (performed within 30 days before or after a pharmacotherapy change) and the percentage of patients with values above those recommended by the American Diabetes Association (ADA) and the American College of Endocrinology (ACE)/American Association of Clinical Endocrinologists (AACE). Results: The study included a total of 7769 T2DM patients (3942 female/3827 male; 56.9% were aged 50-69 years). For patients with no pharmacotherapy change, most did not achieve the ADA recommendations for FPG (56.4% [1917/3398]) or HbA(1c) (48.6% [952/1958]) or the ACE/AACE recommendations for FPG (79.4% [2698/3398]) or HbA(1c) (65.4% [1281/1958]). These patients' mean FPG level was 151.9 mg/dL (95% CI, 150.0-153.9 mg/dL) and their mean HbA(1c) value was 7.51% (95% CI, 7.43%-7.60%). For patients with a pharmacotherapy change, the mean FPG level was 191.1 mg/dL (95% CI, 186.7-195.4 mg/dL) and the mean HbA(1c) value was 8.85% (95% CI, 8.70%-9.00%). Similar to those with no pharmacotherapy change, a large percentage of patients with a pharmacotherapy change did not achieve the ADA recommendations for FPG (77.7% [1107/1425]) or HbA(1c) (76.2% [753/988]) or the ACE/AACE recommendations for FPG (90.1% [1284/1425]) or HbA(1c) (88.5% [874/988]). Conclusion: Despite the proven benefits of maintaining glycemic control and its impact on reducing long-term risk of diabetes complications, these results indicate that the mean FPG and HbA(1c) values for a large percentage of diabetic patients included in this study remained above those recommended by the ADA and the ACE/AACE.