Patients who are Jehovah's Witnesses are known to the medical community for frequently declining blood products, even at times of life-threatening anemia. Alternatives to red blood cell transfusion are being developed, including hemoglobin (Hb)-based oxygen carriers. We present the case of a 77-year-old male Jehovah's Witness who underwent a cystoprostatectomy and radical nephrectomy with a postoperative Hb nadir of 4.5 g/dL. He received an Hb-based oxygen carrier, PEGylated carboxyhemoglobin bovine (Sanguinate), with gradual improvement in anemia symptoms and eventual discharge to a short-term rehabilitation facility.