The Sinergia project SWISS100 is the first nationwide centenarian study in Switzerland. The study began in 2020 and is funded by the Swiss National Science Foundation (SNSF). The original project duration was four years (1.1.2020 to 31.12.2023). With a cost-neutral extension, and the support to foundations (Age Foundation, Fondazione Minerva) the new study end date is 31.12.2024. The project consists of two parts, a cross-sectional SWISS100 Phone Study conducted during the second wave of COVID-19 (2020-2022), and the longitudinal SWISS100 Main Study (2022-ongoing). The data consists of data collected with centenarians in the three main language regions of Switzerland (e.g., German, French, and Italian). SWISS100 focuses on obtaining empirical findings about centenarians in Switzerland and creating a central database. Which includes information about the life situation, characteristics and needs of Swiss centenarians and their families. By combining expertise from the fields of medicine, biology, psychiatry, psychology and sociology, we have developed a multidisciplinary approach to better map and understand the vulnerability and resilience of these very old people. A telephone study was conducted in 2020 and 2021, followed by the launch of the main study in 2022. Currently, a third follow-up of the main study is being conducted. For more information, please visit: https://wp.unil.ch/swiss100/