BACKGROUND: There is limited knowledge on the link between wealth, as well as income, and dementia risk among the oldest old (80 years and over). The purpose of our study was to examine the association between income, wealth, and dementia among the oldest old in Germany. METHODS: We used representative longitudinal data from a survey, which aimed to assess the quality of life and subjective well-being of individuals aged 80 years and above in North Rhine-Westphalia (Germany). The length of follow-up was approximately 2 years. The sample consisted of both community-dwelling and institutionalized individuals, with a total of 943 observations included in the analysis. The average age of the participants was 86.0 years (SD: 4.0 years). Probable dementia was assessed by DemTect, a widely accepted screening instrument. Common income and wealth categories were used to quantify these variables. RESULTS: After adjusting for sociodemographic and health variables, logistic random effects regressions showed that greater wealth was associated with a lower likelihood of probable dementia (second lowest wealth quartile compared to lowest wealth quartile: OR: 0.23, 95% CI: 0.07-0.76; second highest wealth quartile: OR: 0.05, 95% CI: 0.01-0.31; highest wealth quartile: OR: 0.12, 95% CI: 0.02-0.91). In contrast, income was not significantly associated with the likelihood of probable dementia. CONCLUSION: Our study showed a link between wealth and dementia. Such knowledge can enrich poverty and inequality research within this field. More specifically, our findings lend support to evidence-based policies aiming to decrease the burden of dementia in later life through reduction in economic inequalities and better income distribution.