Immune thrombocytopenia (ITP) is an autoimmune hemorrhagic disorder characterized by reduction in platelet counts. T helper 1 (Th1) cells polarization with an increased shift of Th1/Th2 ratio has been reported in ITP. This shift is associated with transcription factor T-box expressed in T cells (T-bet) upregulation and GATA-binding protein 3 (GATA-3) downregulation, leading to an increased T-bet/GATA-3 ratio. Our previous in vitro study showed that recombinant human interleukin-11 (rhIL-11) could normalize Th1/Th2 imbalance in the peripheral blood mononuclear cells (PBMCs) isolated from adult ITP patients, which co-occurred with T-bet/GATA-3 ratio restoration. In this report, we investigated whether rhIL-11 had therapeutic effect in clinical ITP patients and whether rhIL-11 treatment could normalize Th1/Th2 and T-bet/GATA-3 levels in vivo. We found rhIL-11 treatment had a response rate of 67.7% and significantly decreased Th1 and T-bet levels but increased Th2 and GATA-3 levels in ITP patients who showed good response, normalizing Th1/Th2 and T-bet/GATA-3 ratios similar to that in healthy controls. Thus our study suggested rhIL-11 was effective with tolerable adverse effects in ITP. The treatment strategy warrants further clinical investigation.