BACKGROUND: Bell's palsy or idiopathic facial palsy is an acute facial paralysis due to inflammation of the facial nerve. A number of studies published in China have suggested acupuncture is beneficial for facial palsy. OBJECTIVES: The objective of this review was to examine the efficacy of acupuncture in hastening recovery and reducing long-term morbidity from Bell's palsy. SEARCH STRATEGY: We updated the searches of the Cochrane Neuromuscular Disease Group Trials Specialized Register (24 May 2010), The Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 2, 2010), MEDLINE (January 1966 to May 2010), EMBASE (January 1980 to May 2010), AMED (January 1985 to May 2010), LILACS (from January 1982 to May 2010) and the Chinese Biomedical Retrieval System (January 1978 to May 2010) for randomised controlled trials using 'Bell's palsy' and its synonyms, 'idiopathic facial paralysis' or 'facial palsy' as well as search terms including 'acupuncture'. Chinese journals in which we thought we might find randomised controlled trials relevant to our study were handsearched. We reviewed the bibliographies of the randomised trials and contacted the authors and known experts in the field to identify additional published or unpublished data. SELECTION CRITERIA: We included all randomised controlled trials involving acupuncture by needle insertion in the treatment of Bell's palsy irrespective of any language restrictions. DATA COLLECTION AND ANALYSIS: Two review authors identified potential articles from the literature search, extracted data and assessed quality of each trial independently. All disagreements were resolved by discussion between the review authors. MAIN RESULTS: The literature search and handsearching identified 49 potentially relevant articles. Of these, six RCTs were included involving 537 participants with Bell's palsy. Two more possible trials were identified in the update than the previous version of this systematic review, but both were excluded because they were not real RCTs. Of the six included trials, five used acupuncture while the other one used acupuncture combined with drugs. No trial reported on the outcomes specified for this review. Harmful side effects were not reported in any of the trials. Poor quality caused by flaws in study design or reporting (including uncertain method of randomisation, allocation concealment and blinding) and clinical differences between trials prevented reliable conclusions about the efficacy of acupuncture. AUTHORS' CONCLUSIONS: The quality of the included trials was inadequate to allow any conclusion about the efficacy of acupuncture. More research with high quality trials is needed.