Objective: To determine the role of angiotensin converting enzyme (ACE) and angiotensin II type 1 receptor (AT1R) polymorphisms in the pathogenesis of nonartertic anterior ischemic optic neuropathy (NAION). Design: Retrospective, case-control study. Participants: Seventy-four patients with NAION diagnosed from 1984 through 1999. Seventy-one patients who visited the Eye Institute comprised the control group. Testing Intervention: DNA was extracted from whole blood obtained from all patients and control participants. Polymerase chain reaction (PCR) was used for analysis of ACE and AT1R polymorphisms. Results: The frequency of the polymorphism for ACE among the NAION patients (39.2% deletion allele [DD], 54.0% deletion/insertion [D/I] locus, 6.8% insertion allele [II]) was similar to that of the control group (50.7% DD, 39.4% D/I, 9.9% II), with P = 0.21. The frequency of the polymorphism of AT1R in the NAION patients was 5.4% CC, 44.6% CA, 50% AA, and in the control group it was 4.2% CC, 33.8% CA, 62.0% AA, with P = 0.35. Participants less than 55 years of age and those more than 55 had quite similar distributions. Conclusions: Angiotensin converting enzyme and AT1R polymorphisms have no part in the mechanism of NAION. Thus drugs such as ACE inhibitors or AT1R antagonists are not specifically indicated for treatment of these patients.