Objectives The aim of the review was to assess the effectiveness of anti-reflux therapy for patients with hoarseness, in the absence of other identifiable causes, whether or not a definitive diagnosis of laryngopharyngeal and gastro-oesophageal reflux has been made. This was assessed by evaluation of prospective randomised controlled studies that were identified by a systematic review of the literature. Both medical and surgical treatments were evaluated. Method The Cochrane ENT Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL) (Cochrane Library Issue 3, 2005), MEDLINE (1966 to 2005), EMBASE (1974 to 2005) and conference proceedings were searched with prespecified terms. The date of the last search was September 2005.Randomised controlled trials recruiting patients with hoarseness in the absence of other identifiable causes, such as malignancy, cord palsy or nodules, whether or not a definitive diagnosis of laryngopharyngeal and gastro-oesophageal reflux has been made. Data collection and analysis Three reviewers examined the search results and identified studies before deciding which would be included in the review. Results 302 potential studies were identified by the search strategy. No trials were identified which met our inclusion criteria. Six randomised controlled trials were identified in which some, but not all patients presented with hoarseness, and were treated with proton pump inhibition. As we could not determine with certainty whether all these patients had hoarseness among the other laryngeal symptoms, these were excluded. However, these studies suggest a significant placebo response, which is comparable to the benefit derived from anti-reflux therapy in some studies. As no trials met our criteria, we are unable to reach any firm conclusions regarding the effectiveness of anti-reflux treatment for hoarseness. Conclusions There is a need for high quality randomised controlled trials to evaluate the effectiveness of anti-reflux therapy for patients with hoarseness which may be due to laryngopharyngeal and gastro-oesophageal reflux.