A low level of high-density lipoprotein cholesterol (HDL-C) is an important cardiovascular risk factor. Dietary measures and pharmacological agents are often not sufficient to reach the HDL-C target level of 40 mg/dl in patients with low baseline HDL-C. This study assesses the association between lipid levels and age, gender, body mass index (BMI), glycemia, diabetes and smoking and focuses on the parameters influencing HDL-C. In the town of Lede (Belgium) all patients aged between 45 and 64 years were invited during 1999 for a free of charge health check-up and blood test. Blood pressure, weight, length and smoking habits were recorded. Serum levels for glycemia and lipoproteins were determined. In total, 629 subjects attended for the check-up. In a logistic regression analysis age above 50 years was correlated with low HDL-C (OR = 2.27 CI = 1.10-4.68). Male gender was correlated with low HDL-C (OR = 3.85 CI = 1.77-8.43) and with high triglycerides (TG) (OR = 1.94 CI = 1.14-3.30). From the level of 90 mg/dl glycemia was correlated with low HDL-C (OR = 2.56 CI = 1.02-6.39) and high TG (OR = 2.12 CI = 1.16-4.06). Obesity was correlated with low HDL-C (OR = 2.36 CI = 1.18-4.71) and high TG (OR = 2.17 CI = 1.88-5.23). This study provides some evidence to sharpen the target levels for glycemia and BMI among patients with low HDL-C and high TG. For these patients, the target glycemia should be around 90 mg/dl and BMI around 25 kg/m2. Physical activity and diet are also important in the achievement of these target levels.