Introduction: The importance of everyday memory has been advanced in recent years, and which can take practical and broad approach to reflect the memory domains in everyday life. However, few studies have been done on the everyday memory in patients with dementia and little is known about how everyday memory impairments influence their functional performance. Objective: To investigate the specific profile of everyday memory across different domains in dementia and to explore the impact of everyday memory impairments on functional performance. Methods: A total of 40 patients with dementia participated in this study. Their everyday memory performance was evaluated using the Rivermead Behavioral Memory Test-3rd edition (RBMT-3). All participants also completed functional performance assessments, including the Activities of Daily Living Rating Scale II (ADLRS-II), the Personal and Social Performance scale (PSP), the Health of the Nation Outcome Scale (HoNOS) and Dementia quality of life (DEMQOL). Results: 81.3% of participants were found to have impaired everyday memory, predominantly in the verbal and visual memory domains. Significant correlations between the total score of the RBMT-3 and performance on the ADLRS-II, PSP, HoNOS (only in the social subscale), and DEMQOL were presented. Regression analysis indicated that total score of the RBMT-3 predicted all functional performance measures except the HoNOS. Conclusion: There is a high prevalence of everyday memory impairments in patients with dementia, particularly in the verbal and visual memory domains. Everyday memory in dementia is not only related to their functional performance but also can be a predictor of their daily living skills, personal and social functioning, and quality of life. The findings of this study promote our knowledge about everyday