The effects of intravenous infusions of potassium chloride, potassium acetate, potassium aspartate and potassium malate on plasma electrolytes and acid-base balance were investigated in normokalemic or hypokalemic alkalotic rats. Animals who obtained equal volumes of isotonic sodium chloride solution served as controls. All of these potassium solutions increased the plasma potassium concentrations to the same extent. Potassium chloride shifted the acid-base balance to acidotic values in normal rats or corrected metabolic alkalosis in hypokalemic rats. The potassium salts of organic acids, however, caused an increase in alkalosis, acetate acting stronger than aspartate and malate. In potassium deficiency combined with metabolic alkalosis the administration of potassium chloride is preferable to the organic potassium salts since it corrects both the electrolyte disturbances at the same time.