Therapy for post-transfusion purpura (PTP) is controversial. We have evaluated the effect of high-dose IgG (HDIgG) in 11 PTP cases investigated in our institution and summarized the clinical data of 8 additional cases reported in the literature. Two of these 19 cases had to be eliminated from the analysis (1 patient received a total dose of less than 30 g of IgG; 1 patient died 2 days after starting HDIgG therapy from congestive heart failure). Out of a total of 17 cases, 16 had good or excellent response reaching normal platelet values within few days; only one failure was observed. Five patients relapsed, but attained complete remission after a second course (dose) of IgG. Total doses per course ranged between 52 and 180 g of IgG. Five different IgG preparations were used and seemed similarly effective. No adverse reactions were observed. We conclude that HDIgG is the treatment of choice for PTP.