As more individuals undergo autologous bone marrow transplantation (BMT), there is growing interest in the impact of treatment side effects on quality of life. Fatigue is a potentially disruptive treatment side effect that has not been systematically assessed following BMT. The primary aim of this study was to determine whether the severity of fatigue and its impact on quality of life is significantly greater in women who had undergone BMT for breast cancer than in women of similar age with no history of cancer. Another aim was to identify the medical and psychosocial correlates of fatigue in women who had completed BMT. A group of women treated with autologous BMT for breast cancer (n = 43; mean age = 44; mean time since BMT = 20 months) and a group of women of similar age with no history of cancer (n = 43; mean age = 46) participated in this study. Subjects completed measures of fatigue, anxiety, depression, and sleep habits. Medical data were obtained from computerized patient records. Women who had completed BMT for breast cancer reported significantly more frequent and severe fatigue than women with no cancer history. In addition, fatigue had a significantly greater impact on daily functioning and quality of life in BMT recipients than in women with no cancer history. Fatigue following BMT for breast cancer was related to both medical factors (i.e., time since BMT) and psychosocial factors (i.e., anxiety, depressive symptoms and sleep difficulties). Following BMT for breast cancer, women may experience fatigue that is worse than might "normally" be expected and can interfere with daily functioning and quality of life. Future research should focus on identifying the biological correlates of fatigue, psychological and physiological mechanisms by which fatigue is produced, and interventions to alleviate fatigue.