AbstractChronic idiopathic thrombocytopenic purpura (ITP) is an autoimmune disease characterized by the antibody‐mediated destruction of platelets. To maintain the platelets above the symptomatic level we administered 100 μg of anti‐D for 5 consecutive days to 19 children with ITP. Four patients did not respond to the treatment. Fifteen responded with an increase in the average platelet number to 76 000/μL 7 days postinjection. However, the platelet count dropped within 45 days to 27 000/μL. Three months after this study, two patients from the study group were then administered monthly anti‐D after reinjecting anti‐D daily for 5 consecutive days, as previously performed. Platelet levels in these two patients were maintained above 30 000/μL for 5 and 6 months respectively.We concluded that anti‐D administration for 5 consecutive days can induce an increase in platelets followed by a decrease below 30 000/μL after 30–45 days. However, monthly administration of anti‐D after daily injections for 5 consecutive days can keep platelets above the symptomatic level and may provide a corticosteroid‐free safe interval