Obsessive compulsive disorder (OCD) affects the lives of patients as well as their relatives. Calvocoressi et al. (1995) suggested that accommodation (e.g., participating in the patient's rituals) by relatives of patients with OCD was related to global family dysfunction and distress. These investigators did not, however, examine the relationship between family accommodation and severity of the patients' OCD symptoms. In the present study we examined the relationship between families' reactions to the patient's illness (e.g., assistance with rituals, modification of family routine, rejection of the patient, etc.) and the patient's Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) score and Hamilton Depression scale ratings. We also examined the effects of family accommodation and rejection on treatment outcome. Results revealed that family distress, accommodation, and rejection were related to depression and anxiety in the family members, but not to severity of the patients' OCD. At posttreatment, family accommodation and modification of routine was related to the severity of patients' OCD. These results remained significant when the effect of pretreatment OCD severity was partialled out.