A new oral amino acid preparation was given to two groups of patients: group 1, five patients on hemodialysis; and group 2, five patients with chronic renal failure (CRF). In group 1 significant pre- and postdiet changes were: BUN 93–37 mg% (p < 0.01); creatinine 13.0–9.7 mg% (p < 0.001); phosphorus 6.6–4.2 mg% (p < 0.05); uric acid 8.7–6.0 mg% (p < 0.01); C0216.3–21.3 mEq/l (p < 0.01); hematocrit 18.0–20.8% (p < 0.05). In group 2: BUN 93–66 mg% (p < 0.05); phosphorus 5.6–3.8 mg% (p < 0.05); hematocrit 27.3–30.7% (p < 0.05). Nitrogen balance was positive in all patients. It is concluded that this oral amino acid mixture is well-tolerated and can be utilized in CRF to attain