Hemodialysis treatments with large surface area dialyzers were introduced in our dialysis unit since 1974. 129 uremic subjects were treated between September 1974 and August 1988. Age at start of high efficiency therapy ranged between 16 and 72 years; patients survival was: 95.3% at 1 year, 78.3% at 5 years, 65.8% at 10 years. At present 48 subjects are treated with this schedule. The key technical elements for implementation of such program include: high blood flow rates (greater than 300 ml/min), high surface area dialyzers (greater than 1.8 m2), bicarbonate as the buffer source. Traditionally, the rate of ultrafiltration was controlled by monitoring the TMP and the patients body weight, but in some case a preferred approach is the use of an automatic ultrafiltration control system. We conclude that, in a quite large dialysis population, an individualized short dialysis schedule may be safely applied for long time periods.