In a cross-sectional study that aimed to identify risk factors for diabetes, 1290 consecutive, healthy, nonpregnant women of child-bearing age were examined in a center for preventive medicine. An in-depth interview about menses, use of oral contraceptives, and menopause was performed. Plasma glucose at fasting and 2 hours after a 75 gm glucose load, glycated hemoglobin A1c, fasting plasma insulin, total plasma cholesterol, and triglycerides were measured. Compared with nonusers taking no progestogens, oral contraceptive users (n = 431; 33.4%) were younger (p less than 0.001) and leaner (p less than 0.001). After adjustment for age and body mass index, oral contraceptive users had higher 2-hour plasma glucose (p less than 0.001), higher fasting plasma insulin (p less than 0.01), and higher triglycerides levels (p less than 0.01). Fasting plasma glucose, glycated hemoglobin A1c, and total cholesterol did not significantly differ between the two groups. In relation to dosage and types of steroid components, few differences have been found between high-dose and low-dose oral contraceptives or according to the estrogen-progestogen balance of the preparations. Use of oral contraceptives appears to induce an increase of insulin-resistance markers, which have recently been cited as risk factors for ischemic vascular diseases. These markers should be carefully monitored in oral contraceptive users.