Purpose: The purpose of this study was to verify influencing factors affecting service quality provided by caregivers working for the elderly with dementia. Methods: Data were collected using a self-reported questionnaire from 214 caregivers in a long-term care facility in D city. The data were analyzed with service quality, dementia knowledge, work value, and job performance confidence. For data analysis, the descriptive statistics, t-test, one-way ANOVA, Pearson correlation coefficients, and multiple regression were performed using SPSS/WIN 21.0 program. Results: There were significant differences in service quality depending on the health status. Factors influencing service quality were work value, and job performance confidence with R² value of 38%. The highly influencing factors were work value, and job performance confidence. Conclusion: The results of this study indicate that the effort to improve the service quality of caregivers should focus on work value and job performance confidence.