The purpose of this study was to assess the quality of life in women who had previously undergone a bilateral prophylactic mastectomy and to determine what factors predict quality of life in this population. Women in Ontario who had undergone prophylactic mastectomy between 1991 and 2000 were asked to complete several questionnaires that assessed current psychosocial functioning, including the Quality of Life Index (QLI). The mean score for the QLI was 23.34 (range 9.53-30.00). QLI scores were negatively correlated with cancer-related distress, body image difficulties, and psychological distress. Conversely, QLI scores were positively correlated with social support. Significant predictors of quality of life included psychological distress and one subscale of body image (vulnerability). Vulnerability and psychological distress are important predictors of quality of life in women who have previously undergone bilateral prophylactic mastectomy.