Nateglinide is a fast-acting insulin secretion agent that specifically targets postprandial hyperglycemia in patients with type 2 diabetes. The recent reduction in the diagnostic criteria for diabetes and improved understanding of the importance of early insulin secretion served as the rationale for this multicenter, double-blind, randomized, parallel-group, 24-wk study performed in 675 patients with type 2 diabetes but only moderately elevated fasting plasma glucose (FPG) (FPG = 7.0-8.3 mmol/liter) to assess the efficacy and safety of three fixed doses of nateglinide (30, 60, or 120 mg, with meals). A substudy of the effects on early insulin release and prandial glucose excursions following a standardized breakfast was performed in 127 subjects. Nateglinide was well tolerated and elicited a dose-dependent reduction of placebo-adjusted hemoglobin A(1c) (Delta = -0.26 to -0.39%) and FPG (Delta = -0.51 to -0.73 mmol/liter) accompanied by a dose-related increase in suspected hypoglycemic episodes. However, confirmed hypoglycemia occurred in only 5.3% of patients treated with the highest dose, compared with 1.2% in placebo-treated patients (P < 0.05). Nateglinide increased early insulin release and reduced prandial glucose excursions (P < 0.05 vs. placebo). In sum, nateglinide is a safe and effective therapeutic option for treatment of patients with mild to moderate fasting hyperglycemia.