This retrospective study sought to report the spectrum of infections in a homogenous group of 39 patients who underwent implantation of the Thoratec paracorporeal ventricular assist device system (Thoratec Laboratories) in an emergency setting. Thirty-one of the 39 patients developed a total of 99 nosocomial infections (attack rate, 79.5%; incidence, 4.9 per 100 support-days). The lungs were the most frequently involved site (31.3%), and coagulase-negative Staphylococcus species were the pathogens most frequently isolated (16.2%). Infected patients required more transfusions and chest surgical revisions, as well as a longer duration of mechanical ventilation and a longer stay in the intensive care unit, compared with uninfected patients. Cox regression analysis revealed that chest surgical revision was the only independent risk factor for infection at any site (odds ratio, 2.6; 95% confidence interval, 1.2-5.7). There was no significant effect of infection on heart transplantation rate and overall survival.