Purpose: The purpose of this study was to investigate the relationship between social support and loneliness in elderly women living alone. Method: Between 1 October 2008 and 30 April 2009, a random sampling method was conducted to recruit 112 elderly women who were living alone. The subjects were at least 65 years of age. Data was collected using the social support questionnaire, and the translated Korean Version of the Revised University of California at Los Angeles Loneliness Scale (R-UCLA Loneliness Scale). Results: In our study, the sources of social support were the children, neighbours, brothers and sisters, in this order. We found that the loneliness of the subjects was related to age, the number of children, and financial difficulty. The level of loneliness negatively correlated with the social support provided by children, brothers and sisters, other relatives, and neighbours. Also, there was a negative correlation with the social support satisfaction. The social support satisfaction and the social support offered by neighbours and relatives were the significant predictors of loneliness. Conclusion: The sources of social support, such as neighbours and relatives, and the social support satisfaction should be considered when planning intervention by nurses or social workers to decrease the level of loneliness in elderly women living alone.