We have assessed the use of clonidine and bupivacaine for postoperative analgesia. Both drugs were administered via the extradural route, and were given both alone and in combination. The analgesia produced by clonidine was superior to that of bupivacaine; a combination of the drugs resulted in significantly better and longer duration of analgesia than each drug administered alone. Cardiovascular changes and the incidence of side effects were similar in all three groups. The sedative effects of clonidine were not marked.