Abstract. Infection is the second most common cause of death among hemodialysis patients. A predefined secondary aim of the HEMO study was to determine if dialysis dose or flux reduced infection-related deaths or hospitalizations. The effects of dialysis dose, dialysis membrane, and other clinical parameters on infection-related deaths and first infection-related hospitalizations were analyzed using Cox regression analysis. Among the 1846 randomized patients (mean age, 58 yr; 56% female; 63% black; 45% with diabetes), there were 871 deaths, of which 201 (23%) were due to infection. There were 1698 infection-related hospitalizations, yielding a 35% annual rate. . The first infection-related hospitalization was related to the vascular access in 21% of the cases, and non-access-related in 79%. Catheters were present in 32% of all study patients admitted with access-related infection, even though catheters represented only 7.6% of vascular accesses in the study. In conclusion, infection accounted for almost one fourth of deaths. Infection-related deaths were not reduced by higher dose or by high flux dialyzers. In this prospective study, most infection-related hospitalizations were not attributed to vascular access. However, the frequency of accessrelated, infection-related hospitalizations was disproportionately higher among patients with catheters compared with grafts or fistulas.Infection is the second most common cause of death (after cardiovascular disease) among hemodialysis patients (1,2) and is a frequent cause of hospitalization (3). Mortality due to sepsis occurs about 250-fold more commonly among hemodialysis patients than among the general population (4). There is limited literature analyzing the type and frequency of serious infections among hemodialysis patients. Most reported studies are retrospective and have identified diabetes, older age, comorbidity, hypoalbuminemia, and the use of a temporary dialysis catheter as the major, independent risk factors for serious infections (1,3-7).Observational studies have suggested that a higher dialysis dose and use of a high-flux membrane may each decrease the likelihood of infectious events (1,8), but these potential benefits have not been evaluated in randomized studies. The HEMO Study was a large, prospective, multicenter study in which chronic hemodialysis patients were randomized to receive either standard-dose or high-dose dialysis and to use high-flux or low-flux dialyzers, and clinical outcomes tracked prospectively (9). A predefined secondary aim of the study was to determine whether dialysis dose (clearance of small molecules) or membrane flux (clearance of larger molecules) affected infectionrelated deaths or hospitalizations.The present report (1) evaluates the frequency and specific etiologies of infection-related deaths and hospitalizations in this defined patient population (2), assesses whether a higher Kt/V or high-flux dialyzer decreased the likelihood of serious infections, and (3) determines what other baseline clinical factors affect infect...