Objective. To evaluate the frequency of vasculitis, mainly in the forms of Henoch-Schonlein purpura and polyarteritis nodosa (PAN), and to investigate the presence of occult blood in the first stool specimens after an abdominal attack in Turkish patients with familial Mediterranean fever (FMF). Methods. Review of the charts of 207 patients with FMF seen between 1983 and 1993 with respect to clinical vasculitis. A prospective study designed to test the presence of occult blood in the first stool specimens obtained after abdominal attack and at least one week later in 36 patients with FMF compared with healthy and diseased controls. Results. There were 15 patients with Henoch-Schonlein purpura (7%), 2 with definite and one with probable PAN (1%), one of whom developed perirenal hematoma. The diagnosis of FMF was made after the onset of Henoch-Schonlein purpura in 9 and subsequent to the development of PAN in one patient. Occult blood was positive in the first stool specimens obtained after an attack in 17 of the 36 patients with FMF (47%), a finding not reported previously. Conclusion. Vasculitis seems to be an important but not a widely recognized feature of FMF.