The WHO Model List of Essential Medicines has been updated every two years since 1977. The current version, the 20th list, dates from March 2017.

• 20th Edition (March 2017)

• 19th Edition (April 2015)

• 18th Edition (April 2013)

• 17th Edition (March 2011)

• 16th Edition (March 2009)

• 15th Edition (March 2007)

• 14th Edition (March 2005)

• 13th Edition (April 2003)

• 12th Edition (April 2002)

• WHO Model List of Essential Medicines for Children 2011- 3rd Edition.