Over a seven years period, the prevalence of end stage renal failure patients requiring dialysis in a French area of 5.6 10(6) inhabitants was determined by yearly studies. The number increased from 1693 to 2296 (+ 35.6%), a 5% annual increase in the prevalence rate from 311 to 407. No tendency toward a plateau was evident. The main observed changes in the prevalent population were an increasing age (59.4 to 63), mainly for in-center patients, and male/female ratio, the rising of vascular or diabetic nephropathies (de 26.4 to 31.7%), and a decrease in the percentage of in-center dialysis patients (64 to 57%).