Hoarding is associated with problems engaging in social activities, lower social support, increased isolation and poses substantial challenges to family functioning. The aim of this investigation was to explore the relationship between hoarding severity and family and social functioning variables in 60 treatment-seeking adults with hoarding disorder (HD). Participants completed a battery of self-report measures during a baseline assessment completed prior to treatment. Forty-seven percent of participants reported they live alone. Forty-eight percent of participants reported that family and friends never visit them in their home, and 33% indicated they never had visitors to their home, not even service workers or repair people. Twelve percent of participants indicated they never visit with family or friends outside of their home; however, 55% of participants endorsed phoning family or friends more than 9 times each month. Increased clutter and hoarding severity was associated with a lower frequency of family and friends visiting in the home. Family competence and conflict were both positively associated with hoarding severity. Our results shed light on family and social impairment in HD and their relationship with symptom severity; however, additional research should examine social dysfunction among non-treatment-seeking individuals who may be more impaired or isolated.