This study examined whether avoidance, coping efficacy, and perceived control mediate the effects of spouses' unsupportive behaviors on patient psychological distress among 191 married individuals enrolled in cancer treatment. Results of the structural equation analyses suggested that avoidance and coping efficacy mediated the relationship between spouses' unsupportive behaviors and patient psychological distress. Perceived control of emotional aspects of the illness, including emotional responses and relationships with family and friends, and perceived control of the medical course of the cancer did not mediate the relationship between spouses' unsupportive behaviors and patient psychological distress. These findings suggest 2 mechanisms to explain why unsupportive responses from spouses may be associated with psychological distress among cancer patients.