Background: Dementia is a complex condition that affects the elderly and expands global health burdens. Numerous endogenous and external activities can result in the production of reactive oxygen and nitrogen species (RONS). Goal: To evaluate the association between oxidative stress markers and dementia in elderly men. Patients and Methods: A case-control study. Eighty males who were admitted to the Geriatrics and Gerontology Departments at Ain Shams University Hospitals as well as those who were recruited from the geriatric medicine outpatients' clinic were included in the study. The participants were split into two groups: a case group, which consisted of 40 adults with dementia, and a control group, which consisted of 40 participants without dementia. Participants underwent geriatric evaluations, and blood samples were obtained for measurement of oxidative stress blood levels as malondialdehyde (MDA), glutathione peroxidase enzyme (GPX), and total antioxidant capacity (TAC) Results: MDA blood levels were significantly higher in the case group, while GPX and TAC blood levels were significantly lower in the case group. According to statistical analysis, GPX with a cutoff point of 83.2 or lower, TAC with a cutoff point of 20.9 or lower, and MDA with a cutoff point of >82.5; all had high specificity and sensitivity for detecting dementia cases. Conclusion: Higher blood levels of MDA and lower blood levels of GPX and TAC in dementia cases compared to the control group indicate that oxidative stress plays a substantial role in the development of dementia.