Investigations in which quality components influence intervention effects have already revealed that certain characteristics, such as the level of concealment in patient assignment and masking, play an important role. Such investigations will need to continue, particularly around other possible markers or quality such as the language in which the reports are published. For instance, it is unknown whether trials published in non-English journals are of different quality than those published in English language journals. To investigate the effects of language, we compared the quality (and other descriptive characteristics) of 133 English language randomised controlled trials (RCTs) published between 1989 and 1993 in seven general internal medicine journals, with 96 non-English language RCTs published in four languages over the same time period and type of journal. Prior to initiating this project we pilot-tested the data collection instrument, as well as calculating inter-observer reliability to assess quality. The assessment or quality was completed using a rigorously developed scale. All of the results will be presented in detail along with a discussion on the potential impact of the findings.