Background: Age-related macular degeneration (AMD) is the leading cause of blindness in the developed world and is characterized by progressive degeneration of the retinal pigment epithelium and secondary photoreceptor loss, resulting in visual loss. Etiological research suggests that age related macular degeneration is a complex disease, caused by the interactions of several genetic and environmental factors. Polymorphisms in genes encoding the alternative complement pathway, complement factor I (CFI), are associated with the risk for age related macular degeneration. The purpose of this investigation was studying of complement factor I p.Gly119Arg (C.355G>A) polymorphism with age related macular degeneration in the population living in Tehran, Iran. Methods: This case-control study was conducted at Tabriz University from June 2015 to June 2016. In this study the association of p.Gly119Arg polymorphism in complement factor I gene was investigated in 150 patients suffering from age-related macular degeneration and 150 healthy age, sex and ethnicity matched unrelated people as control group. Both of the case and control groups were originated from the population living in Tehran. Genotypes of both groups were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and data was analyzed the Chi-square test in 2x2.Contingency table. Results: Investigation of the association of p.Gly119Arg polymorphism in complement factor I gene with age related macular degeneration showed that there are statistically significant differences between patients and controls in genotype and allele frequencies of this polymorphism (P=0.005 and OR=6.68 in TT, P=0.04 and OR=0.61 in CC, P=0.03 and OR=1.76 in T, P=0.04 and OR=0.56 in C). Therefore CC, TT genotypes and C, T alleles were significantly associated with age related macular degeneration. Conclusion: This study showed a significant association between this polymorphism p.Gly119Arg (C.355G>A) complement factor I gene and age related macular degeneration disease in the population living in Tehran (P<0.05). Our data suggests that this locus polymorphism is not as rare in our studied population as previously reported from different population.