This study has shown that phosphate-buffered sucrose is a suitable preserving solution for the cold storage of rat pancreata for 24 hours. Isotonic citrate does not appear to be as effective a preserving solution under these conditions. Preservation of endocrine function is evident, but preservation of exocrine function is effected by obstruction or occlusion of the ductocystostomy, which may occur some time after transplantation and may not be related to transplant conditions.