The authors describe a group of six patients with pyoderma gangrenosum. In three woman the ulcerative form was on the leg, in one woman the vesicular form changing finto ulcers on the instep of the foot and leg, in one woman the pustulous form on the anterior and posterior surface of the chest and in one man the vegetating form on the chest and lower extremities. Associated diseases were in two instances chronic myeloid leukaemia, once m. Hodgkin, once rheumatoid arthritis, once cholecystitis and chronic hepatitis, once BK positive TB of the lungs stabilized for 10 years. Treatment with systemic cortisonoids was not successful. A verv favourable therapeutic effect was achieved with cyclosporin A - 2.5 mg/kg/day with gradual reduction of the dose to a maintenance dose of 50 mg/day. In four patients the slon manifestations healed within 4 to 24 months. In two patients marked improvement of clinical and slon manifestations occurred within 9 to 22 months. Side-effects of Teatment were not revealed by laboratory and clinical monitoring.

        Key words: pyoderma gangrenosum - cyclosporin A