Patients with chronic renal failure (CRF) are at risk for unique medical emergencies, many of which require hemodialysis for their definitive treatment. This study describes the use of emergency department (ED) hemodialysis in the management of CRF patients. A retrospective chart review was conducted of patients who underwent ED hemodialysis at a regional dialysis center between April 1994 and September 1996. Data were collected on presenting complaint, ED diagnosis, indication for hemodialysis, ED pharmacologic treatment, ED airway management, cardiovascular stability, and disposition. Fifty episodes of ED hemodialysis were identified in 37 different patients. Presenting complaints included: shortness of breath, 38 (69%); weakness, 8 (15%); chest pain, 3 (5%); and other, 6 (11%). ED diagnoses included: congestive heart failure, 36 (65%); hyperkalemia, 13 (24%); and other, 6 (11%). Indications for hemodialysis included: cardiovascular instability, 33 (38%); respiratory distress, 22 (26%); cardiac monitoring, 16 (19%), timing, 13 (15%); and other, 2 (2%). Predialysis stabilization included: nitroglycerin, 29 (26%); sublingual captopril, 17 (15%); calcium chloride, 13 (11%); sodium bicarbonate, 12 (11%); insulin/dextrose, 11 (10%); none, 12 (11%); and other, 18 (16%). Airway support included: noninvasive pressure support ventilation (NPSV), 9 (18%); and endotracheal intubation, 6 (12%). NPSV was provided with a bilevel positive airway pressure system. Three of the endotracheal intubation patients were weaned to NPSV during dialysis, and all NPSV patients were weaned from respiratory support during their hemodialysis in the ED. Some patients had more than one problem. Sixteen patients (32%) were admitted, while 34 (68%) were discharged, including 3 NPSV patients and 22 initially unstable patients. ED hemodialysis in conjunction with additional medical care is a useful emergency medicine technique that can prevent hospital admission in patients with acute renal emergencies.