Intercellular adhesion molecule 1 (ICAM-1) is strongly expressed in vascular endothelial cells and perivascular inflammatory infiltrates in immunopathologic studies of Behçet's disease (BD) lesions. ICAM-1 genes may contribute to the inflammatory events responsible for the vessel damage in BD. We examined potential associations of ICAM-1 gene polymorphisms with BD susceptibility.Case patients were 74 consecutive Italian patients with BD who were followed at the Bologna, Ferrara, Milano, Potenza, Prato, Reggio Emilia, and Trento rheumatology, ophthalmology, and neurology units over a 3 year period (1997-99) who satisfied the International Study Group criteria for BD; 228 healthy Italian blood donors from the same geographic areas were selected as control groups. All BD patients and controls were genotyped by polymerase chain reaction and allele-specific oligonucleotide techniques for ICAM-1 polymorphisms at codon 241 (exon 4) and codon 469 (exon 6).The frequency of R241 was significantly higher in BD patients than in controls (20.3% vs 5.7%; p = 0.001, pcorr = 0.002, OR 4.2, 95% CI 1.9-9.3). The distribution of E/K 469 genotype was similar in patients and controls. Comparing patients with different clinical features, we found only a trend to higher frequency of R241 in patients with articular manifestations (21.4% vs 12.5%; p = 0.08).Our findings show that G/R 241 polymorphism of ICAM-1 is associated with BD susceptibility.