A 55 year-old female with a history of acute intermittent porphyria (AIP) in her twenties was scheduled for left total hip replacement. The clinical symptoms had been mild for the past 30 years, with occasional appearance of muscular weakness in the extremities. Porphyric symptoms were not apparent on the pre-operative round, but urinary porphobilinogen (PBG) was elevated on the pre-operative examination. Anesthesia was induced with propofol and the trachea was intubated by use of suxamethonium. Anesthesia was maintained with inhalation of 1.5-2.0% isoflurane and 50% N2O in O2. Twenty ml of 1% mepivacaine was injected around the wound at the completion of surgery. It was effective for postoperative pain control. We could successfully manage the patient during the intra- and post-operative periods without appearance of porphyric symptoms and increases of PBG and delta-aminolevulinic acid.