In order to control the pain after hemorrhoidectomy and snal fistulectomy, 6 mg of 0.5% hyperbaric tetracaine without (control, group l) or with 0.3mg(group ll) or 0.5 mg(group lll) of 0.1% morphine was injected with a 22 gauge spinal needle into the subarachnoid space through L3-4 interspace of patients in lateral position. About 30 minutes in Fowler' sposition after injection, operation was performed in lithotomy position. All the patients who had morphine showed remarkable relief of postoperative pain for an average of 27 hours. However, the dosage(0.3 or 0.5 mg) or morphine administered did not affect the duration of pain relief. Blood pressure, pulse rate and pulpil size were unchanged in all patients. Dysuria after block developed for on average of 5.6, 13.2 and 14.6 hours in group l, ll, and lll respectively. Most of these cases required urethral catheterization. Minor complications such as nausea, vomiting, itching, fever, burning sensation and paresthesia were observed 16.7, 20 and 20% of cases in group l, ll and lll respectively; however, no treatment was required.