The role of social support was examined in Chronic Fatigue Syndrome (CFS). Social support has been shown to affect illness outcome in medical disorders, likely due in part to communication between patient and support giver on illness-related concerns. Forty-one participants, 25 of whom had a primary support giver, completed the Beck Depression Inventory, the Perceived Stress Scale, the Profile of Mood States, and the Inventory of Socially Supportive Behaviors (ISSB); the primary support giver completed a modified version of the ISSB indicating the level of support he or she provided and a questionnaire assessing beliefs about CFS. Results indicated that there were no differences among individuals with CFS with or without support on measures of mood and perceived stress. Individuals with CFS and their support givers agreed on the amount of support offered, and extent of support was independent of beliefs concerning etiology. Exploratory analyses revealed that verbal emotional-cognitive support generally was more predictive of mental health than was tangible, less communicative support. The lack of positive effect of social support is discussed in relation to the degree of support offered, and implications for future research are discussed.