The aim of the study was to examine the clinical characteristics and prognosis according to severity of thrombocytopenia and response to treatment for thrombocytopenia in patients with systemic lupus erythematosus (SLE).We retrospectively evaluated 230 SLE patients with thrombocytopenia, and reviewed their clinical data and laboratory findings. Thrombocytopenia was defined as platelet counts under 100,000/mm, and patients were divided into 3 thrombocytopenia groups according to severity: mild (platelet counts >50,000/mm), moderate (>20,000/mm, ≤50,000/mm), and severe (≤20,000/mm). Clinical characteristics, treatments, and prognoses were compared among the groups. Furthermore, complete remission of thrombocytopenia was defined as platelet counts >100,000/mm after treatment.There was no significant difference in clinical or laboratory findings among the groups according to severity of thrombocytopenia. However, hemorrhagic complications were more frequent in severe thrombocytopenia (P < 0.001) and mortality was also higher (P = 0.001). Complete remission was achieved in 85.2% of patients. The clinical characteristics and modality of treatment did not differ between the patients with and without complete remission. Mortality in patients with complete remission (1.5%) was significantly lower than in those without complete remission (29.4%, P < 0.001). Survival was significantly higher in patients with complete remission from thrombocytopenia (odds ratio = 0.049, 95% confidence interval: 0.013-0.191, P < 0.001).The severity of thrombocytopenia in SLE patients can be a useful independent prognostic factor to predict survival. Moreover, complete remission of thrombocytopenia after treatment is an important prognostic factor. The severity of thrombocytopenia and response to treatment should be closely monitored to predict prognosis in SLE patients.