We report herein the patterns of type 1 diabetes recurrence in a simultaneous pancreas-kidney transplant (SPK) recipient, in the absence of rejection. A 38-year-old female underwent SPK for end-stage nephropathy secondary to type 1 diabetes. Fasting blood glucose, HbA1c, fructosamine, C-peptide and autoantibodies (GAD-65, IA-2) were monitored throughout follow-up. At 3.5 years post-SPK, HbA1c and fructosamine increased sharply, indicating loss of perfect metabolic control, despite C-peptide levels in the normal-high range. Exogenous insulin was restarted 4 months later. C-peptide levels abruptly fell and became undetectable at 5.5 years. Autoantibody levels, which were undetectable at the time of SPK, never converted to positivity. Pancreas retranspantation was performed at 6 years. The failed pancreas graft had a normal macroscopic appearance. On histology, there were no signs of cellular or humoral rejection in the kidney or pancreas. A selective peri-islet lymphocytic infiltrate was observed, together with near-total destruction of β cells. At 2.5 years post retransplantation, pancreatic graft function is perfect. This observation indicates unequivocally that pancreas graft can be lost to recurrence of type 1 diabetes in the absence of rejection. GAD-65 and IA-2 autoantibodies are not reliable markers of autoimmunity recurrence.