The association between apolipoprotein E (apoE) gene polymorphism and ischemic cerebrovasculardisease (ICVD) has been controversial. These controversies may be due to inaccurateclassification of patients and ethnic differences. The aim of the present study was to assess therelationship between apoE gene polymorphism and the development of ICVD in a populationfrom Korea. We investigated 136 patients with ICVD and 357 controls without ICVD. Nodifferences in the apoE genotypes frequencies (χ2 = 3.660, df = 5, P = 0.454) and even in thealleles frequencies (χ2 = 1.946, df = 2, P = 0.378) were observed in the ICVD patients comparedwith that in controls. The data have been compared with data found in other populationgroups. However, the risk of ICVD associated with apoE ε3/ε4 genotype was increased nearly3-fold in subjects possessing the history of diabetes mellitus (OR 3.3, 95% CI 1.2-9.4, P = 0.026).We concluded that the apoE polymorphism is not associated with ICVD at least in the Koreanpopulation, but the apoE frequencies found in this study differ significantly from thoseobtained in Japanese.