We analysed a large homogeneous group of 14,403 patients transplanted for early leukaemia from an HLA-identical sibling and reported to the EBMT in four time cohorts: 1980-1989 (24%), 1990-1994 (26%), 1995-1998 (30%) and 1999-2001 (20%). We focused on death from infection. End points were survival, death from relapse and transplant-related mortality (TRM), which was subdivided into death from graft-versus-host disease (GvHD) (1315 patients; 25% of deaths), infection (597 patients; 11% of deaths) or 'other' causes (1875 patients; 34% of deaths). Survival increased from 52% at 5 years in the first to 62% in the third cohort (P<0.05) and TRM decreased from 36 to 26% (P<0.05) due to a reduction in death from infection (P<0.001). GvHD, 'other' causes and relapse did not improve. The relative proportions of bacteria (217 patients; 36%), viruses (183 patients; 31%), fungi (166 patients; 28%) or parasites (32 patients; 5%) as cause of infectious death (cumulative incidence of death at 5 years 1.8, 1.6, 1.4 and > or = 0.3%, respectively) and median time to death from infections (3 months (range 0-158 months)) did not change. Death from infections has been reduced significantly, but it still represents an ongoing risk after HSCT and draws attention to the time beyond the initial period of neutropenia.