Current conceptualizations do not adequately explain the particular relational difficulties experienced by young adults who have been faced with the death of a sibling. In this study, the authors explore interrelationships between attachment style, coping style, repressive defensiveness, and the loss of a sibling in childhood. The findings suggest that this type of stressor may result in different coping reactions than other stressors. In particular, sibling loss seems to stimulate greater support seeking than withdrawal, regardless of attachment style. Sibling loss can pose particular relational challenges for the developing child because of the traumatic impact on the primary caregivers. This fact makes it important for therapists to have an understanding of some of the potential consequences of this particular traumatic event.