Background: The rise in human longevity has brought increased academic attention to centenarians, a rare population group often subject to age misreporting. Objective: This paper compares the census counts of centenarians in Argentina in 2001, 2010, and 2022 with estimates derived from indirect demographic methods and alternative data sources. Methods: For the indirect estimation of the centenarians in 2001 and 2010 we use two methods: (1) an r-variable technique based on data from the censuses and life tables, with a battery of sensitivity analyses performed, and (2) a cohort reconstruction based on data from the vital registration system. For the estimation of centenarians in 2022, we use the COVID-19 vaccination database. Results: The indirect estimates of the centenarian population are similar to the censuses of 2001, 2010 and 2022. Contribution: The centenarian population counted in the censuses of 2001, 2010, and 2022 is quite reliable, although a slight overestimation cannot be ruled out. This pattern contrasts with that of Brazil, where centenarian overcounts are more substantial, despite both countries being geographically close and sharing broadly similar socioeconomic conditions. This underscores the importance of national context in shaping the quality of demographic data at very old ages.
