Splenectomy is very effective in patients with idiopathic thrombocytopenic purpura (ITP) unresponsive to steroids; however it is invasive and has been associated with longstanding immune suppression. We retrospectively reviewed the clinical outcome and laboratory parameters in 52 patients who had undergone splenectomy and had been followed up for a minimum of 5 years. We also studied the long term effectiveness of anti pneumococcal vaccination by testing antibody titres against 5 bacterial antigens. Hospital records of 52 individuals with ITP who required splenectomy were accessed. Of these 52, 47 patients were available for clinical review and consented to provide blood samples to have their laboratory parameters repeated. None of the patients had been treated with prophylactic antibiotics. Except for one, all had received anti pneumococcal vaccination before surgery. The serum anti pneumococcal IgG antibody titres were tested by enzyme linked immunosorbent assay and the results were related to a control group. The complication rate of surgery was 15%, but there was no mortality. Immediately post splenectomy all patients normalised their platelet counts but thrombocytopenia recurred in 6, who required further immunosuppression. Following splenectomy the median time to platelet recovery was 10 days (range 1–90). At 5 years from surgery, 92% remained in response and only 1 / 47 surviving subjects required continuing immunosuppression. In the intervening period subsequent to surgery 5 individuals died. Of these deaths, 4 were unrelated to ITP while 1 patient who had not received anti pneumococcal vaccination, developed rapidly fatal sepsis. At review, patients had significantly higher MCV (p= 0.001), lymphocyte count (p= 0.001) and lower IgM (p= 0.0001). Compared to control samples, of the 5 anti pneumococcal serotypes tested, only the 19F antibody titres were significantly reduced (15.07 ± 17.47 vs. 65.26 ± 79.35 pg/L; p= 0.03) in splenectomised subjects. Splenectomy is highly effective in ITP while the rate of short term complications and long term sequelae appear acceptable. In patients receiving vaccination, anti pneumococcal titres were well maintained and despite no antibiotic prophylaxis no patient in this group developed life threatening infections.