Background: Tunisia has experienced a considerable increase in degenerative and debilitating diseases associated with aging including in particular dementia and Alzheimer's disease. These diseases belong to a specific socio-taking health care and it is important to have population estimates to set up appropriate measures. Objective: The aim of this paper is to provide professionals and stakeholders in the gerontology field with a synthesis of available data on the prevalence of dementia in Tunisia in 2001, 2012 and 2030. Methods: Based on a study conducted in 2001, and taking into account the current epidemiological data on dementia, we made an estimate for 2012. This estimate was based on the total number of the Tunisian population in 2012 and the proportion of people aged over 65. From these new data, we were able to make a projection for 2030. Results: The prevalence of dementia of all types can be estimated of around 4.6% in the Tunisian population aged 65 and over in 2012, and the prevalence of Alzheimer's disease of around 3.2%. Thus, the prevalence of dementia of all types has increased by 24% in over 10 years. The projection shows that in 2030 the number of seniors aged 65 and older with dementia syndromes would be around 58,000 patients. As for people of the same age suffering from Alzheimer's disease accounting for 70% of all dementias, their number would reach nearly 40,600 patients. Conclusion: Alzheimer's disease and other dementia will be a major challenge, which Tunisia will face in the coming years, and these both in terms of health, society and economy.