Preservation of cadaveric pancreas allografts has been a difficult problem in clinical pancreas transplantation; most institutions use Collins solution and limit preservation time to less than 6 hr. Longer preservation times have been used at the University of Minnesota. Between August 1983, and December 1985, 47 human cadaveric pancreas grafts were transplanted into Type I diabetic recipients after cold storage at 4 degrees C in a modified, hyperosmolar silica-gel filtered plasma (SGFP), a solution previously found to allow dog pancreas grafts to be successfully preserved for up to 48 hr. Ten grafts were preserved for 2-5 hr (group 1); 20 for 6-11 hr (group 2; 17 for 12-26 hr (group 3). Graft function and late outcome were compared between these groups and another group of 7 cadaveric grafts (group 4), which were transplanted immediately and without any preservation. Analysis of exocrine pancreatic function early after transplantation showed a maximum mean serum amylase (IU/L) of 557, 440, 429, and 307 in groups 1, 2, 3, and 4, respectively. Primary preservation failure rates of 0, 5%, 5.8%, and 0%, and endocrine graft function rates at 1 month of 80%, 80%, 76%, and 86% were obtained for groups 1, 2, 3, and 4, respectively (P = NS). Only patients who were insulin-independent were counted as having functioning grafts. Detailed functional studies at 1 month showed that mean plasma glucose levels during 24-hr metabolic profiles were in the normal range in 71%, 68%, 72%, and 50%, while oral glucose tolerance test results were within the normal range in 38%, 81%, 76%, and 66% of groups 1, 2, 3, and 4, respectively (P = NS). At 1 year, patient survival rates were 57%, 88%, 75%, and 100% (P = NS), and the graft functional survival rates were 0, 25%, 33%, and 29% (P = NS) in the respective groups. Five patients in group 2, and 6 in group 3 have currently functioning grafts at 4 to 37 months after transplantation. We conclude that cadaver pancreas grafts can be safely preserved for 12-24 hr in modified SGFP solution, thus making the sharing of these organs between different centers practical and the transplant operation less of an emergency procedure.