General anesthesia has been improved technically and applied in a wide field of surgery, but the undesirable side effects of inhalational anesthetics and its adjuvants such as muscle relxants have frequently claimed our attention in current anesthetic practice. For these reasons, various techniques of brachial plexus block have been developed for the purpose of surgical, diagnostic and therapeutic procedures. The short duration of local anesthetics requires repeated drug administration for a long lasting operation, therefore drug overdosage may cause toxic reaction. Recently introduced bupivacaine hydrochloride(Marcain), an anilide derivative, has longer duration of action and higher potency than other local anesthetics. Brachial plexus block with bupivacaine hydrochloride and lidocaine was performed on 166 patients undertaking various surgical operations for upper extremities at the Department of Anesthesiology, Pusan National University Hospital form October, 1981 to Mary, 1982, the results were summarized as follows: 1) 156 cases of a total 166 patients had successful operations under brachial plexus block but remained the remaining 10 cases required general anesthesia. 2) There were 9 cases of pulmonary diseases, 17 cardiovascular diseases and 2 nephritis in the preoperative evaluation of the patients. 3) The average duration of analgesia for lidocaine and bupivacaine hydrochloride group was 180 and 360 minutes respectively. 4) Complications and side reaction of brachial plexus block included 3 cases of pneumothorax, 15 Horner's syndrome, 2 hematoma formation and 1 toxic sign.