Meta-analysis is a statistical method for combining the results of available research studies to increase statistical power. The steps of meta-analysis are identification of question, search and selection of trials and analysis. Evidence based medicine (EBM) is integrating individual clinical expertise with the best available external clinical evidence from systematic research. The practice of EBM consists of formulated clinical question, systematic review, critical appraisal, application for patients and performance review. We must notice the results of meta-analysis and evidence are keeping up to date. We should use them with critical appraisal skill and should not criticize without good understanding.