Some high-risk patients with end-stage renal disease (ESRD) cannot tolerate or do not respond to conventional haemodialysis three times per week. Sixteen high-risk ESRD patients were converted from conventional haemodialysis to short daily haemodialysis (sDHD). This consisted of 2 h daily haemofiltration or haemodiafiltration, six times per week. The dialysis response, blood pressure change, weight variations, weekly Kt/V (a measure of the adequacy of dialysis), serum phosphorus, serum albumin, haemoglobin, cardiothoracic ratio (CTR), left ventricular mass index (LVMI) and Short Form Health Survey (SF-36) quality-of-life scales were compared before and after conversion to sDHD. sDHD improved many clinical and biological variables. Weekly Kt/V increased from 4.36 +/- 0.62 on conventional haemodialysis to 4.88 +/- 0.41 after switching to sDHD. Blood pressure normalized, there were significant decreases in episodes of hypotension during haemodialysis, serum phosphorus concentration, CTR and LVMI, and there were significant increases in levels of serum albumin and haemoglobin. Calcium and phosphorus metabolism, and nutritional status were improved. Physical function, physical role, bodily pain, general health, vitality and mental health improved significantly.