A review of hospital epidemiologic data disclosed five cases of polymicrobial bacteremia on a nephrology inpatient service over a period of 30 months. All five cases occurred in patients receiving long-term hemodialysis; four of them had indwelling silicone rubber vascular access devices. Although all patients had risk factors other than uremia and dialysis predisposing to an increased likelihood of infection, no patient had either obvious skin infection at the site of the vascular access or documented visceral infection. One patient died, and the other four recovered after removal of the vascular access device and appropriate antibiotic therapy. The increased risk of polymicrobial bacteremia associated with long-term hemodialysis should be taken into account when empiric antibiotic therapy is undertaken.