Behçet's disease (BD) is a recurrent multi-system inflammatory disorder caused by the combinations of multiple genetic and environmental factors. CCR5 is a Th1-dominant chemokine receptor whose levels are increased in patients with active BD. It is believed that a 32 bp deletion in the CCR5 gene reduces the expression of this receptor on the cell surface. The aim of the present study was to investigate the association of CCR5 delta32 allele with BD in Iranian patients.