Metabolic acidosis is a condition that is commonly encountered in both chronic renal failure and in end-stage renal disease. Metabolic acidosis is associated with many adverse effects: negative nitrogen balance, increased protein decomposition, anorexia, fatigue, bone lesions, impaired function of the cardiovascular system, impaired function of the gastrointestinal system, hormonal disturbances, insulin resistance, hyperkalemia, altered gluconeogenesis and triglyceride metabolism, increased progression of chronic renal failure, and growth retardation in children. Even ‘minor’ degrees of metabolic acidosis are deleterious. Metabolic acidosis of end-stage renal patients could be successfully corrected with bicarbonate hemodialysis and with peroral bicarbonate-containing phosphate binders, i.e. calcium carbonate. Bicarbonate powder compared with bicarbonate solutions has some advantages and enables a stabile composition of electrolytes. ‘High’ dialysate bicarbonate (40– 42 mmol/l) is a safe, well-tolerated and useful tool for better correction of the metabolic acidosis and must become a standard of hemodialysis treatment. Measured postdialysis blood bicarbonate concentration should be obtained at least every month and correction of metabolic acidosis by maintaining serum bicarbonate ≧22 mmol/l should be a goal of the management of patients undergoing chronic hemodialysis.