In two studies of kidney transplant patients and their significant others, the authors examined whether the relations between enacted social support and patient distress were moderated by patients' satisfaction with their relationship with the support provider (i.e., their significant other). In Study 1 (n = 121 couples), unsupportive spousal behaviors were associated with more distress only among patients who were less satisfied with their marital relationship. In Study 2 (n = 112 couples), the relations between unsupportive behaviors and distress again varied as a function of the patient's relationship satisfaction, although the particular pattern of the interaction depended on the specific unsupportive behaviors offered to the patient. In both studies, relationship dissatisfaction was associated with higher levels of patient distress. Supportive behaviors were not related to distress and did not interact with relationship satisfaction. Implications for future research on social support in marriage are discussed.