Excellent response rates are now achieved with modern chemoimmunotherapeutic approaches in chronic lymphocytic leukaemia (CLL), but the disease remains incurable. Younger patients and those with adverse prognostic factors will die from their disease, and are therefore candidates for clinical trials investigating the potential role of haematopoietic stem-cell transplantation (SCT) in the management of their disease. Autologous SCT is feasible and safe, but there is a high incidence of subsequent relapse. Myeloablative allogeneic SCT is associated with high treatment-related morbidity and mortality but few late relapses. Attempts to exploit the graft-versus-leukaemia effect of allogeneic donor cells but to reduce the toxicity are being explored in studies of reduced-intensity conditioning allogeneic SCT in CLL. With many potential treatments available, appropriate patient selection and the timing of SCT in the management of CLL remain controversial and the focus of ongoing clinical trials.