Calcium oxalate deposition in the kidney allograft remains an underappreciated cause of acute graft dysfunction. Diagnoses such as acute rejection, infection, hydronephrosis, and fluid collections are more immediately considered in the early post-transplant period. Risk factors include hyperoxaluria due to chronic fat malabsorption (post gastric bypass, inflammatory bowel disease), a diet rich in salt or animal protein, vitamin C ingestion, volume depletion, diabetes, and delayed graft function. We present the case of a patient who developed acute kidney injury secondary to oxalate nephropathy at 3 months post-transplant. Renal function improved with medical management, including volume repletion, calcium carbonate, and potassium citrate, without the need for hemodialysis. As more dialysis patients with morbid obesity requiring bariatric surgery, diabetes, and metabolic syndrome are being considered for renal transplantation, this entity merits more careful attention both prior to and after transplantation.