Inflammatory processes are considered important in the pathogenesis of Alzheimer's disease (AD). Intercellular adhesion molecule-1 (ICAM-1) is an important mediator of inflammatory response and immune cell activation, is expressed on cerebrovascular endothelium and neuritic plaques in brain of AD patients, and seems to be implicated in the process of neuro-degeneration. A common polymorphism of the ICAM-1 gene (K469E) has been recently reported. In this case-control study, we evaluated the distribution of E/K alleles and genotypes of the ICAM-1 gene in 98 patients affected by sporadic AD and 115 age- and sex-matched controls. The frequency of the EE genotype was significantly higher in AD patients (P<0.01). Logistic regression analysis indicated that the presence of EE genotype significantly increased the risk of AD (odds ratio 3.01 [1.1-8.0], P<0.05). This study shows for the first time an association between ICAM-1 E/K gene polymorphism and AD, suggesting that polymorphisms of the ICAM-1 gene may be clinically important and confirming that inflammatory mechanisms may be crucial in the pathophysiology of neuro-degenerative diseases.