In 1999 the Council for International Organisations of Medical Sciences (CIOMS) began reviewing their 1993 ethical guidelines on biomedical research involving human subjects. The revised guidance, published in August 2002, covers a broader range of topics than the first edition, and includes consideration of the controversial issue of placebo-controlled trials in developing countries (Guideline 11).

While some sections remain similar to the 1993 guidance (such as Guideline 7 on inducements to participate in research) others are substantially changed (for example Guideline 5, which outlines essential information for prospective research subjects). A useful aspect of the CIOMS guidance is the commentary provided for each guideline. For example, while the wording of Guideline 11 is similar to section 29 of the Declaration of Helsinki (with an additional proviso), the accompanying four-page commentary provides a useful reflection on the ethical considerations underlying such a stance.

The Guidance is also available in Spanish.