Phospholipids, constituents of the outer layer of all lipoproteins and cell membranes, have not been measured in epidemiological studies, due to their heterogeneity. Rather, the specific phospholipid subgroups have lately been investigated. Phosholipids and oxidized phospholipids are biologically active molecules and are involved in atherogenesis as well as inflammatory processes and immune responses. In the 2003 screening of the Turkish Adult Risk Factor Study, phospholipids were measured firstly in 452 men and women in the Marmara and Central Anatolian regions. A method that measures the total phosphatidylcholine, sphingomyelin and lyso-phosphatidylcholine was used. Coronary heart disease (CHD) and metabolic syndrome (MS) were encountered in 11.3% and 45.4% of the cohort, respectively. Serum phospholipid levels were found to be significantly different between men (192.2±32.0 mg/dl) and women (204.9±41.2 mg/d). Significant correlations existed between serum phospholipid levels and total cholesterol, apo AII, triglycerides, LDL-C, complement C3, apo B, apo AI and coronary risk score (r>0. 30), HDL-C, diastolic BP, body mass index, metabolic syndrome, waist circumference, fibrinogen, log CRP, log GGT, glucose (r =0.10 to .25), uric acid, log fasting insulin and, inversely, with smoking and physical activity (r =-0.10), and (at borderline significance) with age. Multiple linear regression analysis among 13 risk parameters revealed triglycerides, LDL-C, HDL-C, and complement C3 as independent significant determinants of phospholipid levels. Sex- and age-adjusted OR of phospholipid levels were not found to be significant for prevalant coronary heart disease. Age-adjusted OR of phospholipid levels for metabolic syndrome were found to be significant only in men with 1.013 (%95 1.002;1.023). We conclude that high total phospholipid levels reflect high risk for metabolic syndrome, particularly in men, though these are not independent of the standard components. The age-adjusted risk of these levels in association with CHD which exhibited a trend among women, requires further investigation in the future. Studying their content in the HDL fraction or the specific phospholipids and their oxidized forms in different lipoprotein fractions seem more promising in this regard.