We tested the preservation of the pancreas for 96 h by a modified two-layer (UW solution/perfluorochemical) cold storage method (group 1) in the canine model of pancreas autotransplantation and compared this with an original two-layer (Euro-Collins' solution/perfluorochemical) cold storage method (group 2) and simple cold storage method with UW solution (group 3). A graft was considered functioning if the dog had a normal blood glucose for at least 5 days after transplantation. The functional success rates after preservation for 72 h were 100%, 100% and 80% for groups 1, 2 and 3 respectively. On the other hand, the functional success rates for groups 1, 2 and 3 after preservation for 96 h were 75%, 0% and 0% respectively. The mean K value of 96-hour preserved grafts for group 1 at 2 weeks after transplantation was 1.52 +/- 0.30 compared with 1.98 +/- 0.48 before preservation. Biopsies of grafts from group 1 showed almost normal pancreatic architecture even after preservation for 96 h. In addition, biopsies of grafts preserved for 96 h in group 1 at 4 weeks after transplantation showed almost normal endocrine tissue with mild fibrosis of the exocrine tissue. This study demonstrated the possibility of preserving the pancreas for 96 h prior to transplantation.