We treated 10 patients who had chronic refractory idiopathic thrombocytopenic purpura (ITP) with high-dose dexamethasone (DXM, 40 mg/d for 4 sequential days every month). The interval from diagnosis ranged from 49 to 300 months, and patients had previously received a median of 5.5 treatments (including splenectomy in nine cases). Median platelet count was 14 x 10(9)l (range 6-26 x 10(9)/l) at the onset of DXM and eight patients had bleeding symptoms. Eight patients received at least three cycles of DXM. Five patients had a response (i.e. platelet count at least doubled and increased by > 20 x 10(9)/l), including one almost complete remission and four minor responses (MR). Of the MR, one was probably due to concurrent IVIg administration, and all four MR were transient, in spite of further cycles of DXM. In three patients DXM was a failure after three or four cycles. In two patients DXM had to be stopped after one course because of major side-effects (systemic hypertension with stroke and insulin-dependent diabetes, respectively). In our experience, high-dose DXM had a relatively limited effect in chronic refractory ITP and was associated with severe side-effects in some cases.