In October 2000 — a time when there was great attention and intense public controversy surrounding clinical (especially multinational) research — the World Medical Association (WMA) adopted the 5th revision of the Declaration of Helsinki. These revisions are the most substantial adaptations to be made for 27 years. A commitment to revise the declaration acknowledged that deficiencies and disagreements in interpretation needed to be corrected, and that ethical standards evolve.

This article presents an overview of the process of revision and the major changes made to the declaration. While the authors acknowledge that several of the revisions are clear improvements on the previous version, they also highlight a number of concerns and complain that the new revision is "imprecise and ambiguous". A number of potentially controversial additions to the declaration are specifically identified, including provisions relating to conflicts of interest, monitoring and oversight of research, what should happen after research is over, benefits from research, vulnerable populations, research on those unable to consent and the use of placebo controls.

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