Marfan syndrome is a connective tisuue disorder presenting with multiorgan symptoms. Cases of patients with mental disorders associated with Marfan syndrome were reported previously. We present a case with schizo-obsessive disorder comorbid with Marfan syndrome and literature about this condition will be discusssed. Thirthy nine years old, tall female with long limbs and scoliosis refered 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, and ophtalmology. Although mental diseases associated with Marfan syndrome was 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.