© 2016 Elsevier Ltd Purpose Severe fatigue after treatment of ductal carcinoma in situ (DCIS) has not been studied before. The current study examined (i) the prevalence of severe fatigue in DCIS patients versus breast cancer survivors (BCS) and healthy controls (HC), (ii) quality of life and functioning of severely versus non-severely fatigued DCIS patients and BCS, and (iii) the association of fatigue with psychosocial and behavioral factors in DCIS patients. Methods 89 patients treated for DCIS were matched on age and gender to 67 BCS and 178 HC (ratio 1:1:2). Fatigue was measured with the Fatigue Severity subscale of the Checklist Individual Strength. Results 23% of DCIS patients, 25% of BCS, and 6% of HC were severely fatigued (DCIS versus HC: p <0.001). Severely fatigued DCIS patients had a lower quality of life and were more impaired in all domains of functioning than non-severely fatigued DCIS patients. Sleep problems, dysfunctional cognitions regarding fatigue, avoidance of activities, all-or-nothing behavior, perceived lack of social support, DCIS-related coping problems, and fear of future cancer occurrence were related to fatigue. Conclusions The prevalence of severe fatigue in DCIS patients was similar to BCS, but higher than in HC. Severely fatigued DCIS patients had a lower quality of life and more functional impairments. The psychosocial and behavioral fatigue-related factors in DCIS patients are known to perpetuate fatigue in BCS. These factors can be targeted in interventions for cancer-related fatigue. Our findings suggest that the same treatment elements might be applicable to severely fatigued DCIS patients.