This report presents the recommendations of the WHO Expert Committee responsible for updating the WHO Model List of Essential Medicines. The first part contains a review of the report of the meeting of the Expert Subcommittee on the Selection and Use of Essential Medicines, held in October 2008. It also provides details of new applications for paediatric medicines and summarizes the Committee's considerations and justifications for additions and changes to the Model List, including its recommendations. Part Two of the publication is the report of the second meeting of the Subcommittee of the Expert Committee on the Selection and Use of Essential Medicines. Annexes include the revised version of the WHO Model List of Essential Medicines (the 16th) and the revised version of the WHO Model List of Essential Medicines for Children (the 2nd). In addition there is a list of all the items on the Model List sorted according to their Anatomical Therapeutic Chemical (ATC) classification codes.