The objectives of this study are to: (a) examine the association of loneliness and mistreatment of older Chinese women, and (b) examine the potential modifying effect of social support on these associations. We conducted a cross-sectional study of 141 elderly women presented to an urban medical center. After adjusting for confounders, every 1-point increase in the loneliness score was associated with 44% increased risk for mistreatment. After adding the interaction of social support (social support x loneliness), loneliness was no longer associated with increased risk for mistreatment. Loneliness is a significant risk factor for mistreatment of older Chinese women. Greater social support, particularly perceived social support, may modify loneliness as a risk factor for the mistreatment of older Chinese women.