In this study, we evaluated the genotype profile of GSTM1 and GSTT1 polymorphisms in patient carriers of primary open-angle glaucoma in the population of Goiânia, GO, Brazil. This case-control study included 100 Brazilian patients with glaucoma and 53 patients without glaucoma. Blood samples were genotyped for polymorphisms in GST genes using polymerase chain reaction-based methods. Polymorphism frequencies were compared using the c2 test and odds ratio (α = 0.05). The GSTM1-present genotype was 40% in the glaucoma group and 71.6% in the control group, while the GSTM1 null genotype was 60 and 28.3% in the same groups, respectively. The GSTT1-present genotype was 52% in the primary open-angle glaucoma group and 66% in the control group; the null genotype was 48% in the case group and 34% in the control group. The GSTM1 null genotype was more frequent in the glaucoma group than in the control group (P = 0.0004; odds ratio = 6.7; 95% confidence interval = 2.7- 20.3). The combined GSTM1 null and GSTT1-present genotypes were more frequent in the primary open-angle glaucoma group compared to the control group (P = 0.02; odds ratio = 3.1; 95% confidence interval = 1.2-7.9).