Background: Obstructive sleep apnea syndrome (OSAS) may promote hyperglycemia and insulin resistance. Objective: We studied the link between sleep apnea and microvascular diabetic complications in veterans with type 2 diabetes mellitus (DM-2). Design: A retrospective electronic chart of all veterans referred for sleep studies over a 1-year period was reviewed. Ninety-eight patients with a glycosylated hemoglobin <6.5% were included in the study. The degree of glycemia (HbA1c) and presence of macro-and microvascular complications were compared with OSAS variables. Method: Statistical analysis examined bivariate associations between OSAS variables and metabolic syndrome parameters. Results: The apnea hypopnea index was significantly related to diabetic microvascular complications, particularly retinopathy. Oxygen desaturation was significantly and inversely related to microalbuminuria, microvascular complications, retinopathy, and HbA1c . Conclusions: Sleep apnea is associated with microvascular complications even in well-controlled DM-2 veterans. Clinical implications: Screening for OSAS should be considered in patients with DM-2. Copyright (c) Association of Military Surgeons of the US. All rights reserved.