An approximately 39-year-old female originally wild-caught Hoffmann's two-toed sloth (Choloepus hoffmanni) presented to the veterinary hospital of a local zoo in January 2019 due to a several month history of declining condition characterized by weight loss, lethargy, polyuria, and polydipsia. Multiple anesthetized examinations in that month revealed decreasing body condition, decreasing serum phosphorus levels, and increasing blood urea nitrogen despite unremarkable abdominal imaging and palpation. Due to her declining condition and concerns about her quality of life she was euthanized. Gross and histological examination revealed changes in both of her kidneys consistent with a diagnosis of chronic renal disease. Evidence of chronic renal disease is a common finding in aged sloths at necropsy, but, as seen in this case study, antemortem diagnosis and treatment of this disease in sloths proves difficult.