Age-related macular degeneration (AMD) is a clinically heterogeneous disease and constitutes the major cause of visual impairment in the elderly population worldwide. Rhesus macaques also possess a macula and, like humans, develop drusen-associated, age-related macular pathologies. Susceptibility to AMD in humans and drusen formation in rhesus macaques both have been shown to be associated with variation in the HTRA1 and ARMS2 genes. To corroborate these results we genotyped a cohort of 116 rhesus macaques with and without macular drusen. Like in humans, markers in the two genes showed a significant association with drusen formation at the genotype level. Joint haplotype analysis revealed, however, that the disease association observed in rhesus macaques was entirely attributable to a promoter polymorphism (-558G>T) of the HTRA1 gene.