We report on four cases (three women, one man, age at diagnosis 26-61 years) with severe autoimmune thrombocytopenia (AITP) who were refractory to initial steroid therapy (n = 4), to subsequent splenectomy (n = 2), azathioprine (n = 1), and cyclosporine (n = 1). Over years they received low-dose continuous or intermittent steroid therapy. After 6 to 31 years these patients achieved a "spontaneous" complete remission (CR) (n = 3) or partial remission (PR) (n = 1) unrelated to any specific second or third line treatment; CR/PR are sustained for 0.5+ to 9+ years. These data indicate that spontaneous remissions may occur in AITP even after a long duration of the disease.