Laparoscopic splenectomy (LS) has been reserved for intractable and relapsing immune thrombocytopenic purpura (ITP) despite medical treatment. With further experiences of LS in ITP, we investigated long term outcomes of LS, especially newly developed morbidities, and tried to find predictive factors for favorable outcomes. From August 1994 to December 2004, fifty-nine patients whose follow-up period was more than 12 months after LS were investigated. After a long-term follow-up (median 54 months, range 12.5-129 months), a complete response (CR) was found in 28 patients (47.5%), partial response in 24 (40.7%), and no response in 7 (11.9%). The relapse rate during follow-up periods was 15.2%. The rapid response group (p=0.017), in which the platelet count increased more than twice of the preoperative platelet count within 7 days after LS, relapsing after medical treatment (p=0.02), and the satisfactory group as the initial result of LS (p=0.001) were significant for predicting CR in univariate analysis, but only the initial satisfactory group was an independent predictive factor for CR in multivariate analysis (p=0.036, relative risk=6419; 95% CI, 1.171-35.190). Infections were the most frequent morbidities during the follow-up period, which were treated well without mortality. LS is a safe and effective treatment modality for ITP. Active referral to surgery might be required, considering complications and treatment results related to long-term use of steroid-based medications.