Of 24 dogs subjected to hemorrhagic shock, 12 resuscitated with intravenous infusions containing 2.5 per cent human serum albumin maintained significantly higher, p less than 0.05, serum albumin levels than did 12 others treated with Ringer's lactate solution, with or without 50 per cent dog plasma. These differences persisted for as long as six weeks after hemorrhage. Dogs resuscitated with Ringer's lactate solution and 50 per cent dog plasma had significantly higher serum globulin levels than did the dogs receiving 2.5 per cent albumin containing infusion during the first three days after hemorrhage. The simultaneous addition of 5 per cent glucose, potassium chloride and hydrocortisone sodium succinate to the infusion of dogs receiving 2.5 per cent albumin in Ringer's lactate solution did not provide significant alterations in the serum concentration of protein and protein fractions when compared with those of dogs receiving only 2.5 per cent albumin in Ringer's lactate solution. These findings corroborate the suggestion of a capillary leak of serum albumin into the interstitial space during hemorrhagic shock that persists for at least one week after hemorrhage. The administration of albumin containing solutions during the initial stages of hemorrhagic shock counteracts this albumin loss.