I 131 -albumin metabolic studies were carried out in 5 rabbits before, 3 weeks after, and several months after removal of 70 to 90 per cent of the jejunum and ileum. A sixth animal was studied before and 11 weeks after a sham operation. During postoperative experiments, the animals were found to be in a highly unsteady state with large losses of albumin from the vascular compartment. Despite these losses, the plasma albumin concentration was maintained at a relatively constant level. No decrease in the albumin efflux occurred following nearly complete jejuno-ileectomy. The data suggest that albumin catabolism is a first order process.