['Lysophosphatidylcholine (LPC) is a promising biomarker for atherosclerosis and phospholipase activity. Serum LPC level in patients with coronary artery disease (CAD) was compared with controls.', 'Eighty five CAD patients and 105 controls were enrolled. For sera from both groups of patients, twelve molecular species of LPC and lipid profile were measured. Associations with CAD were investigated and factors affecting serum LPC level were analyzed.', 'Individual LPC species, inter-species ratio, and the ratio to serum lipids were not associated with CAD. Diabetes was associated with decreased level of LPC 16:1. The ratios of LPC 16:0 to LPC 18:1, LPC 16:0 to 18:2, LPC 18:0 to LPC 18:1, and LPC 18:0 to LPC 18:2 were significantly affected by sex. Current smokers had lower LPC 18:0 to LPC 18:1 ratio.'] Is serum lysophosphatidylcholine level altered in coronary artery disease?