OBJECTIVE: To establish whether there is evidence of the efficacy of homoeopathy from controlled trials in humans. DESIGN: Criteria based meta-analysis. Assessment of the methodological quality of 107 controlled trials in 96 published reports found after an extensive search. Trials were scored using a list of predefined criteria of good methodology, and the outcome of the trials was interpreted in relation to their quality. SETTING: Controlled trials published world wide. MAIN OUTCOME MEASURES: Results of the trials with the best methodological quality.