Infection-related mortality (IRM) is responsible for a major proportion of all cases of non-relapse mortality (NRM) after allogeneic PBSCT (alloPBSCT). We analyzed 580 consecutive adults who received a first alloPBSCT from an HLA-identical sibling from 1994 to 2008 at a single institution to describe the severe infections and report the incidence, causes and risk factors for IRM and NRM. Both IRM and NRM decreased with time; within the period of 1994-2000, the 2-year incidence of IRM and NRM was 22 and 31%, respectively, vs 11 and 16% within the period of 2001-2008 (P<0.05 for both comparisons). In multivariate analysis, the variables that increased IRM were within the earlier period of 1994-2000 (P<0.01), poor performance status (P<0.01), grade II-IV acute GVHD (P<0.001) and invasive fungal infection (IFI) (P<0.001) or CMV disease (P<0.001) after transplant. With respect to NRM, earlier time period was also identified as a risk factor (P<0.001), as well as IFIs (P<0.001) and CMV disease (P<0.001). The intensity of the conditioning regimen had no effect on IRM and NRM. These results showed a significant reduction in IRM and NRM over a period of 15 years. The development of IFIs and CMV disease continue to have an impact on NRM.