There were 160 incidents associated with regional anaesthesia amongst the first 2000 incidents reported to the Australian Incident Monitoring Study. They were categorised into 6 groups; epidural anaesthesia (83), spinal anaesthesia (42), brachial plexus blocks (14), intravenous local anaesthesia (4), ocular blocks (3), and local infiltration (14). The largest single cause of incidents involved circulatory problems; these occurred in all the groups except brachial plexus block (30 cases of hypotension, 7 of arrhythmias, 3 of cardiac arrest, 2 of hypertension and 1 of myocardial ischaemia). There were 24 drug errors, of which 10 involved the "wrong drug" and 4 "inappropriate use". With the exception of these, all the remainder involved problems specific to regional anaesthesia: 26 inadvertent dural punctures; 19 failed or inadequate blocks; 14 dural puncture headaches (all cured by blood patches); 10 inadvertent total or high spinal blocks (of which 7 required artificial ventilation); 5 blocks on the wrong side or in the wrong patient; 3 late hypoxic incidents and a variety of miscellaneous problems. Three-quarters of all incidents occurred in the presence of an anaesthetist and over 90% in patients of ASA Groups I-III. Rapid recognition by the anaesthetist prevented many potentially life threatening events, and the only death was as a result of surgical bleeding.