A 72-year-old man with end-stage renal disease (ESRD) undergoing transurethral resection of a bladder tumor experienced severe and prolonged hypotension after receiving oral 5-aminolevulinic acid (5-ALA). Continuous infusions of norepinephrine and vasopressin ultimately resolved the hypotension over the course of 26 hours. It is uncertain whether 5-ALA is causative or is a contributing factor that influences other factors, such as hypovolemia after hemodialysis and autonomic nerve dysfunction associated with ESRD. Our findings suggest that anesthesiologists should be aware of the possible occurrence of hypotension after administration of 5-ALA, and urologists should consider intravesical 5-ALA administration in patients with ESRD.