Objectives: With the surge in the elderly population, a growing interest in the prevention and treatment of geriatric diseases has been observed, along with awareness of the severity of problems associated with dementia, a cognitive impairment. The purpose of this study was to investigate the correlation between chewing ability and cognitive function among elderly people residing in a rural area. Methods: A total of 162 elderly individuals, aged between 65 and 97 years, were surveyed. Trained examiners conducted interviews and assessments of chewing ability, on the basis of the number of remaining teeth, denture status, masticatory performance evaluating gum, ShadeEye-NCC measuring overall change in color of the gum (ΔE), and T-Scan^®III analyzing distribution of occlusion patterns. Cognitive function was assessed using the Korean version of the Mini-Mental State Examination-Dementia Screening (MMSE-DS) tool. Results: Participants with a low score in the MMSE-DS were found to have distinguishably lower denture need, smaller number of remaining teeth, and lesser color change in the masticatory performance evaluating gum. In the cognitive impairment group, a tendency of having unilateral and anterior occlusion led to occlusal discomfort and chewing difficulties. Conclusions: The study highlights important associations between chewing ability and cognitive function. The finding corroborates that tooth loss may be a predictive risk factor for cognitive impairment.