NETosis, a novel form of neutrophil-related cell death, acts as a major regulator of diabetes and diabetes-associated complications. In this review, we show that the extrusion of neutrophil extracellular traps, termed NETs, plays an important role in the pathogenesis of type 1 diabetes mellitus (T1DM), type 2 diabetes mellitus (T2DM), and diabetes-induced complications. In T1DM, β-cell death induces the sequestration of neutrophils in the pancreas and seems to be correlated with increased NETosis. In T2DM patients, products of NETs release are significantly elevated. Increased levels of dsDNA are correlated with the presence of cardiovascular disease and diabetic kidney disease, further supporting the role of NETosis in the pathogenesis of other diabetes-induced complications such as impaired wound healing and diabetic retinopathy. NETosis is induced by high glucose through incompletely understood mechanisms, but it also appears to be elevated in patients with diabetes who have tightly controlled glucose levels. We hypothesize that hyperglycemia worsens the already elevated baseline of NETosis in diabetic patients to further increase its detrimental effects.