Single nucleotide polymorphism (SNP), rs11200638, in the promoter of HTRA1 has recently been shown to increase the risk for AMD. In order to investigate the association of this HTRA1 polymorphism and the bilaterality of AMD, we genotyped rs11200638 in control, unilateral, and bilateral advanced AMD patients. The A allele for SNP rs11200638 in HTRA1, was significantly more prevalent in bilateral wet AMD and GA patients than in unilateral groups (p=.02 and p=.03, respectively). The homozygote odds ratios of bilateral wet AMD and GA are significantly greater than those seen in unilateral groups (twofold and threefold increase, respectively). This finding is consistent with the role of HTRA1 in AMD pathogenesis and will help aid in the clinical management and prognosis of AMD patients.