INTRODUCTION: To keep up appearances, people with dementia sometimes pretend to know the correct answer, as seen during administration of neuropsychological tests such as the Mini-Mental State Examination (MMSE). These saving appearance responses (SARs) of people with dementia often lead to caregivers and/or medical staff underestimating the severity of dementia and impede proper early initiation of treatment. However, most descriptions of SARs are based on empirical knowledge of clinicians. In this study, we investigated whether SARs are typical communication patterns in people with Alzheimer's disease (AD), compared with mild cognitive impairment (MCI) or dementia with Lewy bodies (DLB). METHODS: The participants were 107 outpatients with AD, 16 with mixed AD with cerebrovascular dementia, 55 with MCI, and 30 with DLB. We assessed the occurrence of SARs during the MMSE. The relationships between the SARs and AD were examined by the χ2 test and logistic regression analysis. RESULTS: People with AD who showed SARs were 57.9%, whereas those with MCI were 18.2% and DLB were 20.0% (P with Bonferroni correction < 0.05). Although there were significant differences in some variables in each group of diagnosis, logistic regression analysis showed that people with AD were more likely to show SARs than those with MCI (Odds ratio = 3.48, 95% Confidential Interval = 1.18-10.28) and DLB (Odds ratio = 4.24, 95% Confidential Interval = 1.50-12.01), even after controlling for sex, estimated disease duration, MMSE, and frontal assessment battery scores. CONCLUSION: The occurrence of SARs could be found most frequently in people with AD. Clinicians should develop a respectful attitude toward dementia patients with SARs because SARs imply conflicted feelings about questions that patients cannot answer correctly.