Abstract: Splenectomy may lead to a good response in 60–80% of adult patients with corticosteroid refractory idiopathic thrombocytopenic purpura (ITP) but, the long-term response to splenectomy still remains less well defined. We assessed the long-term efficacy and safety of splenectomy in adult patients with chronic ITP. A cohort of 59 splenectomised ITP patients (M/F = 25/34; median age 39 yr; range 14–75) were followed up for a median of 18 yr (range 2–32). No life-threatening surgical complications were observed. The overall response rate was 78% with 59% complete remission (CR) and 19% partial remission (PR). CR and PR patients were younger than non-responding patients at time of diagnosis (median age: 36 yr vs 48 yr, P = 0.03) and at splenectomy (median age: 38 yr vs 51 yr, P = 0.02). Among the 46 responding patients, eventually 17 had relapse. No disease progression occurred after 12.1 and 7.3 yr for patients in CR or PR, respectively. One case of fatal septicaemia was recorded. We conclude that splenctomy is an effective and safe treatment in adult patients with chronic ITP failing to respond to corticosteroid treatment and importantly, our findings support the view that response to splenectomy is durable after a certain point in time.