Lipoprotein(a)[Lp(a)] is a LDL-like particle with a glycoprotein called apo(a) attached to its apoB through disulfide bond. Many case-control studies support the opinion that plasma Lp(a) levels were associated with coronary artery disease. This study was conducted to assess the relationship between plasma Lp(a) level and coronary artery disease in Korean population. Serum levels of Lp(a), in addition to other lipids and known clinical risk factors for coronary artery disease were determined in 92 subjects undergoing coronary angiography. Among them 30 patients had no obstruction in the coronary artery(cath-control group), while the others revealed the presence of coronary artery stenosis more than 50%(CAD group). The Lp(a) levels of the CAD group were significantly higher the those of cath-control group(31.8±25.0mg/dl vs 14.6±11.9mg/dl, p<0.005). Other lipids except triglycerides(166.9±70.5mg/dl vs 116.2±56.1mg/dl, p<0.005) were not significantly different between two groups. The patients with significant coronary artery disease of two or more vessels were found to have higher Lp(a) levels than those of one vessel disease. Lp(a) levels had no relations with other lipids, diabetes, smoking, hypertension and age. Stepwise discriminant analysis revealed that Lp(a) was the best discriminator among risk factors for coronary artery disease. These results suggested that Lp(a) level was a significant independent risk factor for coronary artery disease.