BACKGROUND AND OBJECTIVE: To evaluate the long term efficacy of treatment with intravenous iloprost for severe Raynaud's phenomenon (RP) and ischemic leg ulcers in patients with autoimmune systemic diseases. PATIENTS AND METHOD: Prospective observational study over 2 years with iloprost (intravenous infusions, 0.5 to 2 ng/kg/min, initial cycle of 5 consecutive days and maintenance infusions during 24 h monthly, lengthened when it was needed) in patients with severe RP and ischemic leg ulcers whithout response to conventional therapy. Treatment was halted in patients with a good response after one year of treatment, with regular clinical controls. RESULTS: We treated 23 patients. Iloprost reduced significantly the mean number (SD) of monthly episodes of RP (150.38 [102.04] initially and 40.05 [78.06] at the end; p < 0.0005), the mean highest duration of episodes of RP (21.86 [26.96] min initially and 7.14 [9.87] min at the end; p = 0.013), the associated pain (p = 0.005), and the mean number of ischemic digital (4.25 [2.86] initially and 0.63 [2.25] at the end; p = 0.003) and leg ulcers (1.67 [0.52] initially and 0.33 [0.52] at the end; p = 0.01). Articular symptoms and inflammatory markers did not improve. Treatment was stopped in 8 patients (in 5 for a very good evolution and in 3 for other causes), and only 1 of them needed to be treated again. Side effects were seen in all cases but always disappeared after slowing infusion. CONCLUSIONS: Iloprost was effective in the long term treatment of severe RP and ischemic leg ulcers in patients with autoimmune systemic diseases.