Objectives: The rapid aging of Taiwan's population has brought attention to issues related to dementia. This study explores the situations that bank tellers may encounter with customers suspected of having dementia and the subsequent decisions made by the tellers. Methods: Bank tellers from two financial institutions who had interacted with customers suspected of having dementia were surveyed using an open-ended questionnaire. The experiences of the tellers were categorized into various case scenarios involving potential financial abuse. Next, bank tellers across 32 branches of a third financial institution were surveyed using a structured questionnaire. Multiple linear regression and logistic regression analyses were employed to evaluate the bank tellers' risk assessment scores, decision-making processes, and other related risk factors. Results: A total of 163 valid responses to the structured questionnaire were obtained and included in the analysis. The results indicated that the financial abuse risk score is positively correlated with the probability a bank teller choosing to decline services. Conclusions: This is the first study in Taiwan to investigate dementia-friendly banking. This study found a high correlation between bank tellers' assessment of the financial risk of customers suspected of having dementia and their decision-making. We recommend that banks provide educational training on dementia-related issues to increase bank tellers' awareness of the risk of financial abuse among customers suspected with dementia.