Alzheimer's Disease International is the worldwide federation of Alzheimer associations that represent people with dementia and their families. Alzheimer's Disease International has commissioned a number of World Alzheimer Reports since 2009 and was involved in the recently launched report Dementia: A Public Health Priority by the World Health Organization. From these reports, we can learn about the growing impact of Alzheimer's disease and other dementias on our societies and the need to take action. Developing national Alzheimer plans is a key tool for this action.