This chapter focuses on the critical appraisal of randomised controlled trials of treatment or preventive interventions and the presentation of study details from these in systematic reviews. Critical appraisal of study reports for systematic reviews is generally a two-stage process. Firstly there is "study selection" where potentially eligible studies are checked to see if they meet the pre-specified inclusion criteria of the review. Then there is "quality assessment" of and data collection from the studies that meet the inclusion criteria. The format and content of text and tables presenting the details of studies included in literature reviews and other work depend on the aims, destination and readership of the intended report. The critical appraisal of studies and the succinct presentation of study details are essential components of evidence-based anaesthesia. Both assist the interpretation of the evidence from studies in terms of its validity and, if valid, its applicability.