Curiosity in older adults is considered to be an important factor in healthy aging, but uncertainties remain about the mechanisms underlying curiosity in later life. For instance, research on curiosity demonstrates different age-related patterns depending on the measurement approach. Questionnaires about everyday life show that curiosity in older adults is often lower than in younger adults, while experimental studies evoking curiosity in the moment, using materials like trivia questions, often demonstrate higher scores in older compared to younger adults. One potential explanation for this opposing age difference is tip-of-the-tongue (TOT) states, which is the feeling of knowing a word while experiencing an inability to retrieve it. These states occur relatively more often in experimental settings (for 20–25% of trivia questions) than in everyday life (a few times a week according to diary studies). Interestingly, these states are also more frequently experienced in older than in younger adults and positively predict state curiosity. In our presentation, we present results from our study, where we examined the role of TOT states in explaining differences in state curiosity between younger and older adults. 171 older and 171 younger adults were presented with trivia questions; they were asked to guess the answer, indicate whether they experience a TOT state, and report their curiosity about finding out the answer. We expected to see higher levels of state curiosity in older adults than in younger adults, and we hypothesized that this effect would be at least partially mediated by TOT states.