OBJECTIVE: To define the incidence, clinical presentation, radiologic findings and principles of diagnosis, and management of acute graft pancreatitis occurring more than 3 months after transplantation. SUMMARY BACKGROUND DATA: Acute graft pancreatitis is a frequent late complication after simultaneous pancreas-kidney transplantation (SPKT) with enteric drainage that is not well understood. METHODS: We performed a retrospective analysis of data from patients who underwent SPKT with enteric drainage at our institution. All recipients who experienced episodes that met the clinical criteria for late graft pancreatitis were included. We excluded events proven to be anastomotic or duodenal stump leaks. Clinical presentation, laboratory findings, radiologic imaging, course of management, and graft and patient outcome were evaluated and analyzed. RESULTS: Of 79 SPKTs (1995-2007), 11 (14%) recipients experienced 31 episodes of late graft pancreatitis (average number per patient, 3; range, 1-13), occurring an average of 28 months after transplantation (range, 3 months to 8 years). All patients presented with right lower quadrant abdominal peritonitis, fever, and findings compatible with pancreas graft inflammation on computed tomography or ultrasound imaging. Mild hyperamylasemia (>110 IU/L) was found in 82% of cases. Treatment was conservative, including bowel rest, antibiotics, and percutaneous sampling and drainage of abscesses as necessary. Excellent graft and patient survival were achieved. CONCLUSION: The diagnosis of late acute graft pancreatitis is clinical, with confirmatory computed tomography or ultrasound imaging. Conservative treatment yields excellent graft and patient survival.