Marfan Syndrome is a connective tissue disorder presenting with multi-organ symptoms. Cases of patients with mental disorders associated with Marfan syndrome was reported previously. We present a case with schizo-obsessive disorder comorbid with Marfan syndrome and literature about this condition will be discussed. Thirty-nine years old, tall female with long limbs and scoliosis referred to psychiatric policlinic with her relatives with complaint of frequent hand washing, anger and doubt against her family and escapes from home. The patient who has delusion of persecution and reference did not have nearly any social activity. The diagnosis of Marfan syndrome was confirmed by history and physical examination with consultation to cardiology, medical genetics, ophthalmology. Although mental diseases associated with Marfan syndrome were documented in literature, Marfan syndrome with schizo-obsessive disorder was not coincided until now. Clinical presentation of a case with burdened family history which was not reported previously is noteworthy. [Anadolu Psikiyatri Derg 2013; 14(3.000): 283-286]