Background: Cochrane abstracts are the most frequently accessed and used part of a Cochrane review. In randomized trials, evidence shows that authors don’t always report the primary outcome in the abstract, and are more likely to report a clinically or statistically significant outcome. This may also be the case in abstracts of systematic reviews. Aim: To assess whether reporting of outcomes is consistent between the full text and abstract of Cochrane reviews. Methods: We included all new reviews published in Issue 4, 2009 of The Cochrane Database of Systematic Reviews, where the primary outcome(s) were clearly stated in the full text and a meta-analysis had been conducted (n = 64); we excluded non-intervention reviews. We assessed the nature of any non-concordance between the full text and abstract in reporting of primary and secondary outcomes. Results: The median number of primary outcomes per review was two (range 1 to 10). Only 44 (69%) reviews reported all primary outcomes from the text in the abstract. Twelve (19%) reported only some of the primary outcomes in the abstract, compared with the full text, and eight (13%) failed to report any primary outcomes in the abstract. Of the 56 (88%) reviews that reported one or more primary outcomes in the abstract, only four (7%) stated this was a primary outcome, and only eight (14%) reported the relative and absolute effect size and 95% confidence interval or P-value. In 33 reviews (59%) there was no absolute effect size given, in 11 (20%) the result was only stated as ‘‘significant’’ or ‘‘not significant’’, in three (5%), only a NNT was given, and in one (2%) only the relative effect size was stated with no P-value or confidence interval. Conclusions: Our preliminary findings suggest evidence of incomplete and selective reporting in abstracts of Cochrane reviews. Detailed analysis will be presented at the Colloquium.