Purpose: This study was done to identity the spiritual state of elderly women who live alone, and factors which affect their spiritual well-being. It was a predictive study using correlations. Methods: Data were collected to identify spiritual well-being of underprivileged older women who live alone and their demographic characteristics, activities of daily living, social support, self-efficacy, and health promotion behavior. Participants were 210 underprivileged women, over 65 years of age and living in permanent-rented apartments in Kyonggi Province. Collected data were analyzed using Pearson correlation coefficients and stepwise multiple regression analysis. Results: Scores for spiritual well-being were higher than the medium, 3.77, out of a possible 6. Health promotion behavior (${eta}$=.22, t=3.51, p=.001), religion (${eta}$=.38, t=7.95, p<.001), self-efficacy(${eta}$=.25, t=4.63, p<.001), social support received (${eta}$=.23, t=3.96, p<.001), length of time living alone (${eta}$=.12, t=2.51, p=.013), and age (${eta}$=.11, t=2.24, p=.026) were significant factors affecting spiritual well-being. Conclusion: The result of the study indicate that to enhance the well-being of underprivileged elderly women, it is necessary to increase health-promotion activity rates and identify mediation strategies to promote social support and self-efficacy.