Hoarding Disorder (HD) is characterized by a difficulty discarding possessions and leads to the accumulation of clutter, causing marked distress and impairment (Mataix-Cols, et al., 2010). HD has been an increasing area of research and public interest, though little is known about how it develops or factors that influence its expression (Mataiz-Cols, Fernandes de la Cruz, Nakoa, and Pertusa, 2011; Frost, Steketee, and Tolin, 2011). High frequency of trauma among people with hoarding behavior has been reported (Saxena et al. 2011; Cromer, Schmidt, and Murphy, 2007; Hartl, Duffany, Allen, Steketee, and Frost, 2005), but none have examined it in detail. The current study included 211 HD diagnosed participants from Frost et al.'s (2011) study of comorbidity, 105 of whom had experienced a traumatic life event and 106 who had not. Severity of acquisition and clutter (SI-R) were elevated among those who had experienced a traumatic life event, while difficulty discarding was not. Interference in the activities of daily living due to hoarding (ADL-H) was greater in participants with a trauma history, as were Clutter Image Ratings. Saving Cognitions Inventory subscales of Emotional Attachment, Responsibility, and Control were higher for participants with versus without trauma. Age of hoarding onset was earlier for participants who had experienced trauma, and participants with trauma histories more often reported lower levels of family warmth and security as well as higher levels of uncertainty. Trauma in hoarding was associated with greater attention deficit disorder symptoms, more anxiety, greater anxiety sensitivity, and more symptoms of obsessivecompulsive disorder. However, trauma was not associated with depression, social anxiety or perfectionism. Participants with histories of trauma had more current Axis I diagnoses, but not over the course of a lifetime. MDD was more frequent in HD participants with trauma, as was GAD. Social Phobia and OCD comorbidity did not significantly differ between participants with and without traumatic life experiences.