Spinal anaesthesia is considered to be a safe and effective method of providing anaesthesia for a variety of surgical procedures. Recently, observations have been made that associate the use of hyperbaric lidocaine with bilateral leg pain. We report nine patients who developed strikingly similar neurological symptoms following routine spinal anaesthesia using hyperbaric lidocaine 5% solutions. All patients had their anaesthesia and surgery in the ambulatory or "short stay" care setting. In each patient, moderate to severe, bilateral, posterior, leg pain developed within 24 hr of the anaesthetic administration. The pain was described as either sharp or cramping with or without associated back pain. None of the patients demonstrated objective neurological deficits. In all cases the symptoms resolved fully within one week. The dose of lidocaine administered in these nine patients ranged from 40 to 100 mg. Although the aetiology of the symptoms is not clear the local anaesthetic or its formulation may have been responsible.