Background: Apolipoprotein E (apoE) plays a major role in lipoprotein metabolism and lipid transport. Associations between apoE genotypes, coronary artery disease (CAD) and other risk factors have been described by many investigators. The aim of this study was to investigate the role of apoE gene polymorphism and other risk factors in the development of CAD in subjects whose coronary arteries were evaluated by means of coronary angiography. Methods: The study population consisted of 199 subjects (114 male and 55 female). Of the total, 107 had CAD. The apoE gene was amplified by polymerase chain reaction (PCR) and then digested by CfoI restriction enzyme. The plasma lipid levels and other risk factors were also determined in all subjects. Results: The epsilon2 and epsilon4 allele frequencies and genotypes carrying epsilon4 allele were significantly higher in CAD (+) patients. Plasma lipids except triglycerides were increased in CAD (+) cases. We found that apoE genotypes, HT, DM, male gender, age and smoking were the independent predictors of CAD. There was no association between apoE alleles and lipids. Conclusion: We conclude that apoE polymorphism (presence of e4 allele) is associated with the development of CAD in Southern Turkey. In our study, we did not observe any effect of apoE alleles on lipid levels. (C) 2001 Elsevier Science B.V. All rights reserved.