Recent data from the CAMPATH users group are reported. Different protocols have been tested using the CD52 antibodies Campath-1M and Campath-1G for prevention of GVHD and graft rejection in allogeneic transplants from both sibling and volunteer unrelated donors. Leukaemia relapse remains a significant problem for patients with CML, but in other diseases the recent results using T cell depletion appear to be as good as, or better than, published data with conventional GVHD prophylaxis. In addition, the morbidity and mortality associated with chronic GVHD are substantially reduced. Future collaborative studies to consolidate these findings include a randomised trial of the humanised antibody Campath-1H organised under the auspices of the EBMT. There are also plans to carry out experimental studies using Campath-1 antibodies to deplete T cells from peripheral blood stem cell harvests.