• The treatment of metabolic acidosis is one of many problems encountered in the premature infant during the first days of life. In this study, 11 infants with gestational ages of no more than 34 weeks were given sodium acetate as a continuous infusion from the first day of life. The daily sodium supply was set at 3 mEq/kg. The arterial serum pH was less than 7.30 in infants at the following ages: 1 to 3 hours, four; 24 hours, two; 48 hours, one; and 72 hours, one. The base deficit was calculated to be less than 5 in four infants at the age of 1 to 3 hours, in one infant at 24 hours, in one infant at 48 hours, and in no infants at 72 hours. The serum sodium concentrations were normal. The continuous infusion of sodium acetate seems to be suitable for the slow correction of metabolic acidosis, and the daily sodium supply of 3 mEq/kg gives a stable serum sodium concentration in the premature infant with a gestational age of no more than 34 weeks.