We present data from an exploratory study of 174 adults with Marfan syndrome regarding their cognitive perceptions of the condition as postulated by the self-regulatory model (Leventhal H, Benyamini Y, Brownlee S et al. In: Petrie KI, Weinman JA, eds. Perceptions of Health and Illness: Current Research and Applications. Amsterdam, The Netherlands: Harwood Academic, 1997: 19-45; Leventhal H, Nerenz DR, Steele DJ. In: Baum A, Taylor SE, Singer JE, eds. Handbook of Psychology and Health. Hillsdale, NJ: Lawrence Erlbaum Associates, 1984: 219-252). The vast majority of the respondents had adequate general knowledge about Marfan syndrome. Eighty-three percent of the respondents perceived Marfan syndrome as having had significant adverse consequences on their lives. Having striae, pain (sore joints), and depression were each independently correlated with this view. Fifty-eight percent of the respondents indicated that they felt they had low to moderate control over their condition, demonstrating variability. History of aortic dissection, pain (sore joints), and depressive symptoms were each negatively correlated with the view that Marfan syndrome is a curable/controllable condition. Moreover, approximately 28% view the condition as a lethal condition, whereas 67% view it as a serious condition. Forty-four percent of the cohort were found to have significant symptomatology of depression independent of beta- and Ca2+-channel blockade use. Respondents cited both advantages and disadvantages of being affected. Genetic counseling that addresses patients' perceptions of Marfan syndrome, and its associated pain, fatigue, and depressive symptoms, may enhance patient adaptation to the condition.