Purpose: To investigate whether normal tension glaucoma (NTG) is associated with increased risk of developing dementia/Alzheimer disease (AD). Methods: A total of 69 patients with NTG were identified in the case note files in the Glaucoma Clinic, University Hospital of Copenhagen (Rigshospitalet), Denmark from 1980 to 2001. The rate of a subsequent diagnosis of dementia as recorded in nationwide health care registers from 1980 to 2005 was estimated and compared with the rate for the general population [standard mortality rate (SMR) = observed number of cases of dementia/expected number of cases of dementia]. Results: The 69 patients had a median age of 64 years (quartiles 57 and 73) at the time of the diagnosis, and the average follow-up period was 12.7 years. The SMR(dementia) was 0.20 (95% CI 0.01-1.11). No patient developed AD. Conclusion: Normal tension glaucoma was not associated with an increased risk of developing dementia/AD.