In this prospective pilot study, nine patients suffering from complex regional pain syndrome of the arm were treated with morphine 0.16 mg h-1 (3.84 mg day-1) applied continuously through an axillary brachial plexus catheter. In all of them an oral analgesic medication including the less potent opioid tramadol had not provided sufficient pain relief. During regional treatment, patients were kept in hospital and physiotherapy was carried out frequently in order to improve strength and function of the affected arm. Pain at rest and during movement as well as grip strength were assessed at first visit, during morphine infusion and at a long-term follow-up visit. All assessments improved significantly during plexus analgesia. There were no major opioid related side-effects. The results from this pilot study indicate that continuous axillary brachial plexus analgesia with low dose morphine might be beneficial in patients suffering from complex regional pain syndrome of the arm.