BackgroundEmphysematous pyelonephritis represents an acute and necrotizing infection characterized by the accumulation of gas within the kidney. This condition poses a swift progression toward sepsis, leading to a poor prognosis. We experienced a rare case of emphysematous pyelonephritis in a nonfunctioning renal allograft attributed to antibody‐mediated rejection after kidney transplantation.Case presentationA 71-year-old man with diabetes had undergone living-donor renal transplantation from his wife. Unfortunately, the transplanted kidney’s function declined due to antibody-mediated rejection, necessitating the introduction of hemodialysis 12 months post-transplantation. Subsequently, 4 months after initiating hemodialysis, the patient presented with pain and swelling in the right lower abdomen. A computed tomography scan revealed the enlargement of the transplanted kidney and gas formation. This constellation of symptoms led to the diagnosis of emphysematous pyelonephritis, resulting in his hospitalization. Further contrast-enhanced computed tomography scans demonstrated an absence of arterial flow and ischemia within the renal allograft. Despite antibiotic treatment and percutaneous drainage, both the gas and fluid in the renal parenchyma and surrounding tissue displayed minimal reduction. Given these compelling findings, an allograft nephrectomy was performed 20 days into his hospital stay. Pathological examination confirmed complete allograft necrosis, revealing nonviable renal parenchyma. The patient’s postoperative recovery progressed favorably.ConclusionsInstances of emphysematous pyelonephritis within transplanted kidneys are infrequently documented. Among these cases, emphysematous pyelonephritis in a nonfunctioning renal allograft is very rare and may be associated with graft ischemia and the presence of injured tissue. The determination of an immediate diagnosis and surgery is important.