BackgroundUremic encephalopathy is uncommon yet is one of the most severe complications of renal failure. We present a case of acute renal failure and associated cerebral and vascular lesions consistent with uremic encephalopathy in a rhesus macaque (Macaca mulatta). MethodsA 14-year-old, female, specific-pathogen-free rhesus macaque presented in lateral recumbency, obtunded, severely dehydrated, and hypothermic, with severe azotemia, mild hyponatremia, hypokalemia, hypochloremia, increased anion gap, and hypercholesterolemia. Due to poor prognosis, the animal was euthanized and a complete necropsy was conducted. ResultsThe animal had diffuse proximal renal tubular epithelial necrosis and loss; regeneration of tubular epithelium was not observed. There was bilateral necrosis and loss of neurons and glial cells in the hippocampus and deep cerebral cortex with edema and multifocal areas of hemorrhage. ConclusionWe present the first reported case of uremic encephalopathy in a rhesus macaque and describe the associated cerebral and vascular lesions.