Sixteen patients were given thoracic epidural analgesia at the T5-T6 level with 2 ml of 1.0% bupivacaine solution plain for pain relief after upper abdominal surgery. In 13 cases the analgesia was prolonged by continuous injection of 1.0% bupivacaine for 24 or 48 h. Onset time and segmental spread of the analgesia are presented as well as segmental spread, intensity of the blockade, and peak expiratory flow rates during prolongation. Signs of tachyphylaxis were noticed, and also signs of accumulation of bupivacaine in plasma. A high incidence of urinary retention occurred. The method is not considered to be ideal for pain relief after upper abdominal surgery.