This study aims to assess the relationship between nutritional status and cognitive decline in a population of non-institutionalized elderly patients evaluated in a geriatric outpatient setting. Data from 144 patients admitted to the general geriatric outpatient services of Luigi Vanvitelli University Hospital (Naples, Italy) and San Felice a Cancello Hospital (San Felice a Cancello, Italy) were collected between January 1 and December 31, 2017. Cognitive function was evaluated through the mini-mental state examination and nutritional status was assessed through mini nutritional assessment. Logistic regression was used to assess the association between clinical characteristics and nutritional status, and it is reported as unadjusted, adjusted for age and sex, and adjusted for other potential confounding factors. In the unadjusted model, poor nutritional status was associated with a worse cognitive deficit (odds ratio (OR)=2.36; 95% confidence interval (CI)=1.77-3.55). The association remained significant after adjusting for age and sex (OR=2.36; 95% CI=1.77-3.55) and in the fully adjusted model (OR=2.92; 95% CI=1.90-5.64). In patients with dementia, malnutrition represents a significant burden that grows heavier as the disease progresses.