Immune thrombocytopenia (ITP) comprises a heterogeneous group of disorders characterized by autoimmune-mediated platelet destruction and impairment of thrombopoiesis. ITP may occur in the absence of an evident predisposing etiology (primary ITP) or secondary to a growing list of associated conditions (secondary ITP), and must be differentiated from other causes of thrombocytopenia. This review focuses on primary ITP in adults. The traditional goal of therapy in this population is to achieve a hemostatic platelet count of 30 × 109/L or above for most patients while minimizing treatment-related morbidity. This approach has been called into question by the recent advent of well-tolerated and effective agents for the management of ITP, including pulse-dose dexamethasone, rituximab, and the thrombopoietin receptor agonists. Recent studies suggest the potential for aggressive therapy at the time of diagnosis to alter the natural history of ITP and point to the importance of quality-of-life considerations in therapeutic decision making.