Background: The CONSORT Statement aims to improve reporting of RCTs, enabling readers to understand a trial’s design, conduct, analysis and interpretation, and assess the validity of its results. Objective: To examine the reporting of RCTs published before and after the revision of the CONSORT Statement in 2001. Design: We examined all primary reports of RCTs published in PubMed in December 2000 (n=517) (Chan and Altman 2005) and December 2006 (n=620). We included parallel-group, cross-over, cluster, factorial and split-body design studies; cost-effectiveness and diagnostic studies were excluded. Data were analysed using STATA; calculating the relative and absolute percentage improvement (with 95% confidence intervals) between 2000 and 2006. Results: The majority of RCTs were two-arm (73% in 2000 vs. 76% in 2006), parallel-group trials (74% vs. 80%), published in speciality journals (93% vs. 90%), with a median sample size of 52 (IQR 24-120) in 2000 and 62 (IQR 33-150) in 2006. The number of drug trials decreased between 2000 and 2006 (76% vs. 57%) and surgical trials increased (10% vs. 21%). More articles reported details of the primary outcome (RR 1.18; 1.04 to 1.33), power calculation (RR 1.66; 1.40 to 1.95), random sequence generation (RR 1.61; 1.31 to 1.96) and allocation concealment (RR 1.40; 1.11 to 1.76) in 2006. There was no difference in reporting of blinding (RR 0.99; 0.90 to 1.09), with a slight decrease in reporting of attrition (RR 0.81; 0.68 to 0.96) in 2006. In 2006, 28% of RCT reports included a CONSORT flow diagram and 62% gave the funding source; very few reported details of trial registration (9%) or access to the trial protocol (1%). Conclusion: Without important information about trial conduct it remains difficult to gauge the validity of its results. Despite some progress in reporting of methodological details in recent years, there remains considerable room for improvement.