Splanchnic nerve block (SNB) is performed to relieve intractable upper abdominal pain caused by carcinoma of the upper G-I tract. Not all patients achieve satisfactory pain relief; therefore, a second or third nerve block trial may need to be performed. In this study, an attempt was made to analyze the possible factors which might affect the result of repeated SNB in 42 the patients among 264 patients who received SNB at Severance Hospital during the period from January 1985 to December 1989. The results are as follows: 1) Among the 42 patients, including 30 males and 12 females, the fifties and forties were the major age groups. 2) Among the underlying diseases, stomach cancer was the most common (18 cases) and pancreatic cancer was next (14 cases). 3) The main locations of pain were the upper abdomen, epigastrium and entire abdomen in decreasing order. 4) Among the thirty-nine cases of first SNB combined with ascites, 13 cases received a repeat block, 81.0% of whom had had metastatic lesion. 5) There were 54.2% who had had single or combined treatment, operation, chemotherapy or radiotherapy before SNB. 6) Twently seven cases (64.3%) had received opioid medication for pain control. 7) In the 75% alcohol group, 11.7% of patients required a second block, and in the pure and 50% alcohol group, 9.6% of patients required a second block within two weeks of the first block. Three cases in both of these repeated block groups required a third block; representing 3.9%, of the 75% alcohol group and 1.6% of the pure and 50% alcohol group. 8) The volume of alcohol used was more than 16 ml bilaterally in both cases. 9) The points of the inserted needle were positioned in the upper and anterolateral part of the $L_1$ vertebra on both sides on the anteroposterior roentgenogram. The contrast media was spread upward along the anterior margin of the vertebral body and posteriorly in repeat block. The frequency of repeat block was higher in cases with ascites or metastasis. The instance of repeat block within 2 weeks of the first block was lower in the pure and 50% alcohol group than in the 75% alcohol group. Thus, alcohol concentration and patient status may be considered factors which influence the result of repeated SNB. We suggest early application of SNB in upper abdominal cancer patients.