The purpose of this study was to determine if breast cancer survivors (BCS) with insomnia can be grouped according to their level of fatigue. A secondary data analysis was conducted on baseline data obtained from a randomized clinical trial that focused on a cognitive-behavioral intervention for insomnia in BCS. Participants were BCS (n = 86) with insomnia who were at least 3 months after completion of primary treatment without current evidence of disease. Three subgroups of women were identified with significant differences in fatigue, including exhausted (35%), tired (41%), and restored (24%). Results suggest that most women have moderate to severe fatigue many years after completion of treatment. Severe fatigue was associated with higher levels of other symptoms and poorer quality of life (exhausted subgroup). Significant differences in insomnia severity, anxiety, depression, and quality of life were noted among the exhausted, tired, and restored subgroups. The existence of fatigue-based subgroups offers important information when providing care to BCS. By determining symptoms associated with fatigue, patient care will benefit through a shift in focus from treatment of a single symptom such as fatigue to the delivery of a tailored intervention that targets multiple symptoms.