Purpose: Late allograft failure (LAF) is a common cause of end stage renal disease (ESRD). These ESRD patients face unique challenges regarding Graft Intolerance Syndrome (GIS) and Sensitization. This retrospective study reports the imaging, pathologic and sensitization findings of LAFs. Methods: 33 patients who had CT scans after LAF were divided into GIS group comprising of 22 patients while 11 had Retained Quiescent (RQ) allografts. Information on dimensions, renal volume and fluid collections were compared between the two groups. Sensitization data and Histopathologic data of renal explants were also collected. Results: The CT scans of GIS group revealed swollen allografts with significantly larger renal volumes in comparison to eleven quiescent allografts which were shrunken and atrophic.Table: No Caption available.Fourteen patients in the GIS group underwent transplant nephrectomy which revealed grade II or higher acute cellular rejection on a background of grade 3 chronic active T cell mediated rejection with findings of hemorrhage and infarction. The renal volumes on imaging and weight of explants nearly matched and did have some correlation with operative blood loss. All explants were C4d negative. An overall trend towards increased sensitization over time was seen in both groups. GIS patients experienced a major upswing in sensitization at, or prior to, the time of their symptomatic presentation. Conclusions: There are salient radiographic differences between GIS and RQ allografts and the CT scan findings can be used as a surrogate marker for expected pathological findings. Our work supports that sensitization has already occurred at GIS presentation. Future studies should focus on interventions to avoid sensitization and GIS.