Eight newborns with a mean gestational age of 36.1 weeks and a mean weight of 2863 grams were treated intravenously with 3% gammaglobulin (Sandoglobulina). We used two different infusion rates: one, of 0.5-1.5 mg/kg/min., and a second one, of 7-9 mg/kg/min. Close cardiopulmonary monitoring was carried out by bioelectronic means. The changes of heart rate, mean blood pressure and respiratory rate before and during the gammaglobulin infusion were recorded. We did not find any significant variation between the values recorded before and during the infusion. These values were all within tolerable physiological ranges except for those for respiratory rate, where 7 out of 8 patients had mild tachypnea. Stable sick newborn because of bacterial infections tolerated well the infusion of intravenous gammaglobulin at rates of 0.5-9.0 mg/kg/min., when the doses used were between 0.25 mg/kg/day and 1.0 gm/kg/day, for 4-6 days.