In the present study we compared the effect of bicarbonate dialysis versus acetate dialysis on iPTH. This study included 20 C.R.F patients and 10 normal control. At the start: for all patients and controls lab investigations (urea, creatinine, Ca, Po4, ALP, serum bicarbonate, iPTH) done. Thin patients subdivided into 2 groups group I continued dialysis on acetate for 6 months. Group II contined dialysis on bicarbonate for 6 months. At the end of 6 months all previous investigations done. We found that group II who continue on bicarbonate dialysis had highly significant lower value of iPTH and highly significant increase in serum bicarbonate.