Relapsed or refractory classical Hodgkin lymphoma (HL) remains a therapeutic challenge. Patients with relapsed HL should be identified according to their prognostic factors at relapse (duration of remission and extranodal disease or stage). Patients with refractory disease, defined as progression during induction treatment or within 90 days after the end of treatment, have the worst prognosis. Following non-crossresistant salvage chemotherapy to achieve cytoreduction, high-dose therapy (HDT) and autologous stem cell transplantation has been shown to be better than conventional-dose chemotherapy for first-relapse/refractory HL. For patients with very unfavorable relapse or primary refractory HL, outcome remains poor with HDT. For these patients, the role of tandem HDT or allogeneic stem cell transplantation will be discussed. In this setting, novel investigational treatments will be presented.