The most important disadvantage of surgical mask usage is that it can aversely affect communication. This study aimed to evaluate the possible effects of face masks on the cognitive test performance of older adults. A total of 198 geriatric patients were enrolled after applying the exclusion criteria. Within the comprehensive geriatric assessment (CGA), cognitive status assessment was performed with the Mini-Mental State Examination test (MMSE) and Quick Mild Cognitive Impairment Screening test (Q-MCI) tests. The median age was 70 (66-77) years, and there were 119 female (60.7%) patients. Patients were divided into normal cognitive status (NC), mild cognitive impairment (MCI), and probable Alzheimer's disease (AD) groups. There were 129 (65.2%), 30 (15.2%), and 37 (18.7%) patients in each group, respectively. For differentiating MCI from NC, calculated optimal cut-offs for the Q-MCI and MMSE total scores were ≤50 (sensitivity 83.3%, specificity 90.7%) and ≤26 (sensitivity 63.3%, specificity 87.5%), respectively. For differentiating AD from MCI, calculated optimal cut-offs for the Q-MCI and MMSE total scores were ≤28 (sensitivity 76.8%, specificity 86.7%), and ≤24 (sensitivity 94.4%, specificity 64.5%), respectively. Our results revealed that screening tests are still sensitive in discriminating cognitive disorders although cut-offs are lower with mask usage than for previously validated cut-offs. This is the first study revealing the impact of surgical mask usage on cognitive test performance, indicating that cut-offs validated before the pandemic may cause overdiagnosing of cognitive disorders since the previous cut-offs are not validated for mask usage. Large sample studies are needed to determine new cut-offs validated with mask usage.