<p>This study identified factors associated with the occurrence of delirium and adverse events (AEs) among elderly inpatients with dementia undergoing ophthalmic surgery in Japan. A retrospective observational study was conducted using the medical records of 128 elderly dementia inpatients who underwent ophthalmic surgery at Juntendo Tokyo Koto Geriatric Medical Center between 2010 and 2021. The sample size (<i>n</i> = 128) was based on available records. For patients with multiple admissions (<i>n</i> = 3), only the first admission was analyzed. Kaplan–Meier survival curves and multivariate logistic regression were used to analyze the impact of patient demographics, comorbidities, anesthesia methods, and other factors on the incidence of delirium and AEs. Delirium was observed in 24 patients (18.75%) and AEs in 6 patients (4.68%). A composite adverse outcome (CAO), defined as the occurrence of delirium or AEs, was present in 23.49% of the patients. General anesthesia (GA) was associated with a significantly higher risk of these outcomes (hazard ratios [HR]: 2.35, 95% confidence interval [CI]: 1.05–5.28). In addition, male patients exhibited a higher risk (HR: 2.44; 95% CI: 1.01–5.87). Delirium tended to manifest earlier in the hospital stay. Delirium and AEs are prevalent in elderly dementia patients undergoing ophthalmic surgery, with GA and male sex as significant risk factors. To mitigate these risks, perioperative strategies should incorporate cognitive screening, anesthesia optimization, and delirium prevention. Individualized anesthetic planning is essential. Future studies with larger cohorts are needed to validate these results and enhance care for this vulnerable population.</p>