We analyzed CIBMTR data to evaluate the incidence of non-relapse mortality (NRM) and association with overall survival (OS) for bacterial blood stream infections (BSIs) occurring within 100 days of alloHCT in 2 different phases: pre-/peri-engraftment (BSI very early phase, BSI-VEP) and BSI post-engraftment (BSI occurring between 2 weeks after engraftment and day 100, late early phase, BSI-LEP). Of the 7128 alloHCT patients, 2656 (37%) had > /=1 BSI by day 100. BSI-VEP, BSI-LEP, and BSI-Both constituted 56% (n = 1492), 31% (n = 824), and 13% (n = 340) of total BSI, respectively. Starting in 2009, we observed a gradual decline in BSI incidence through 2012 (61-48%). Patients with BSI-VEP were more likely to receive a myeloablative conditioning (MAC) regimen with total body irradiation (TBI). NRM was significantly higher in patients with any BSI (RR 1.82 95% CI 1.63-2.04 for BSI-VEP, RR 2.46, 95% CI 2.05-2.96 for BSI-LEP, and RR 2.29, 95% CI 1.87-2.81 for BSI-Both) compared with those without BSI. OS was significantly lower in patients with any BSI compared with patients without BSI (RR 1.36, 95% CI 1.26-1.47 for BSI-VEP; RR 1.83, 95% CI 1.58-2.12 for BSI-LEP: RR 1.66, 95% CI 1.43-1.94 for BSI-Both). BSIs within day 100 after alloHCT are common and remain a risk factor for mortality.